endogenous (adj.) Look up endogenous at Dictionary.com
"growing or proceeding from within," especially with reference to a class of plants including cereals, palms, plantains, etc., 1822, from endo- "within" + -genous "producing."
endometrium (n.) Look up endometrium at Dictionary.com
"lining membrane of the uterus," 1882, medical Latin, from endo- + Greek metra "uterus," related to meter (see mother (n.1)). Related: Endometrial (1870).
endomorph (n.) Look up endomorph at Dictionary.com
1940 as one of W.H. Sheldon's three types of human bodies, from endo- + -morph, from Greek morphe "form" (see Morpheus). Earlier, "a mineral encased in the crystal of another mineral" (1874). Related: Endomorphic.
endorphin (n.) Look up endorphin at Dictionary.com
"chemical which occurs naturally in the brain and works like morphine," 1975, from French endorphine. First element from endogène "endogenous, growing within" (see endo- + genus); second element from morphine.
endorse (v.) Look up endorse at Dictionary.com
c. 1400, endosse "confirm or approve" (a charter, bill, etc.), originally by signing or writing on the back of the document, from Old French endosser (12c.), literally "to put on the back," from en- "put on" (see en- (1)) + dos "back," from Latin dossum, variant of dorsum "back" (see dorsal). Assimilated 16c. in form to Medieval Latin indorsare. Figurative sense of "confirm, approve" is recorded in English first in 1847. Related: Endorsed; endorsing.
You can endorse, literally, a cheque or other papers, &, metaphorically, a claim or argument, but to talk of endorsing material things other than papers is a solecism. [Fowler]
endorsement (n.) Look up endorsement at Dictionary.com
1540s, from endorse + -ment. Figurative use from 1630s. Earlier endosement (early 15c.).
endoscopy (n.) Look up endoscopy at Dictionary.com
1861, from endo- + -scopy.
endoskeleton (n.) Look up endoskeleton at Dictionary.com
1838, from endo- + skeleton.
endosperm (n.) Look up endosperm at Dictionary.com
1819, perhaps from German, from endo- + sperm.
endospore (n.) Look up endospore at Dictionary.com
1859, perhaps from French, from endo- + spore.
endothermic (adj.) Look up endothermic at Dictionary.com
1866, from French endothermique; see endo- + thermal.
endow (v.) Look up endow at Dictionary.com
late 14c., indowen "provide an income for," from Anglo-French endover, from en- "in" (see en- (1)) + Old French douer "endow," from Latin dotare "bestow" (see dowry). Related: Endowed; endowing.
endowed (adj.) Look up endowed at Dictionary.com
1700, past participle adjective from endow.
endowment (n.) Look up endowment at Dictionary.com
mid-15c., "action of endowing," from endow + -ment. Meaning "property with which an institution or person is endowed" is from 1590s; that of "gift, power, advantage" is early 17c.
endpoint (n.) Look up endpoint at Dictionary.com
also end-point, 1844, originally in geometry, later chemistry; from end (n.) + point (n.). General use by 1920s.
endue (v.) Look up endue at Dictionary.com
also indue, c. 1400, "invest (with) some gift, quality, or power" (usually passive), from Old French enduire, induire "lead, drive, initiate, indoctrinate" (12c.) and directly from Latin inducere "to lead" (see induce). Related: Endued.
endurable (adj.) Look up endurable at Dictionary.com
c. 1600, "able to endure," from endure + -able, or from French endurable. Meaning "able to be endured" is from 1744. Related: Endurably.
endurance (n.) Look up endurance at Dictionary.com
late 15c., "continued existence in time;" see endure + -ance. Meaning "ability to bear suffering, etc." is from 1660s.
endure (v.) Look up endure at Dictionary.com
late 14c., "to undergo or suffer" (especially without breaking); also "to continue in existence," from Old French endurer (12c.) "make hard, harden; bear, tolerate; keep up, maintain," from Latin indurare "make hard," in Late Latin "harden (the heart) against," from in- (see in- (2)) + durare "to harden," from durus "hard," from PIE *dru-ro-, from root *deru- "be firm, solid, steadfast" (see true).

Replaced the important Old English verb dreogan (past tense dreag, past participle drogen), which survives in dialectal dree. Related: Endured; endures.
enduring (adj.) Look up enduring at Dictionary.com
"lasting," 1530s, present participle adjective from endure.
Endymion Look up Endymion at Dictionary.com
beautiful youth, son of Jupiter and Calyce, beloved by Moon-goddess Selene, from Greek, perhaps literally "diver, plunger," from endyein "to enter into, sink into, plunge, dive," which was used in reference to the sun or stars setting into the sea. On this theory, he originally was a solar deity, a personification of the setting sun.
enema (n.) Look up enema at Dictionary.com
early 15c., via Medieval Latin, from Greek enema "injection," from enienai "to send in, inject," from en "in" (see en- (2)) + hienai "send" (cognate of Latin iacere; see jet (v.)).
enemy (n.) Look up enemy at Dictionary.com
early 13c., "one hateful toward and intent on harming (someone)," from Old French enemi (12c., Modern French ennemi), earlier inimi (9c.) "enemy, adversary, foe; demon, the Devil," from Latin inimicus "an enemy," literally "an unfriend," noun use of adjective meaning "hostile, unfriendly" (source also of Italian nemico, Catalan enamic, Spanish enemigo, Portuguese inimigo), from in- "not" (see in- (1)) + amicus "friend" related to amare "to love" (see Amy). From c. 1300 in English as "adversary of God, unbeliever, heathen, anti-Christian;" late 14c. as "the Devil;" also late 14c. as "member of an armed, hostile body in a war, feud, etc.;" of the opposing military forces as a whole, from c. 1600. From mid-14c. as an adjective.

Most Indo-European words for "personal enemy" cover also "enemy in war," but certain languages have special terms for the latter, such as Greek polemioi (distinct from ekhthroi), Latin hostis, originally "stranger" (distinct from inimicus), Russian neprijatel' (distinct from vrag). Russian vrag (Old Church Slavonic vragu) is cognate with Lithuanian vargas "misery" (see urge (v.)), and probably is related to Proto-Germanic *wargoz, source of Old Norse vargr "outlaw," hence "wolf;" Icelandic vargur "fox;" Old English wearg "criminal, felon;" which likely were the inspirations for J.R.R. Tolkien's warg as the name of a kind of large ferocious wolf in "The Hobbit" (1937) and "Lord of the Rings." Related: Enemies.
energetic (adj.) Look up energetic at Dictionary.com
1650s, "powerful in operation," from Greek energetikos "active," from energein "to work, be in action, act upon" (see energy). Of persons, "active," in English from 1796 (energetical "operative" is from c. 1600; from 1630s as "full of energy," while energical is attested from 1560s). Related: Energetically.
energize (v.) Look up energize at Dictionary.com
1751; see energy + -ize. Related: Energized; energizing.
energizer (n.) Look up energizer at Dictionary.com
1750, agent noun from energize.
energy (n.) Look up energy at Dictionary.com
1590s, "force of expression," from Middle French énergie (16c.), from Late Latin energia, from Greek energeia "activity, action, operation," from energos "active, working," from en "at" (see en- (2)) + ergon "work, that which is wrought; business; action" (see organ).

Used by Aristotle with a sense of "actuality, reality, existence" (opposed to "potential") but this was misunderstood in Late Latin and afterward as "force of expression," as the power which calls up realistic mental pictures. Broader meaning of "power" in English is first recorded 1660s. Scientific use is from 1807. Energy crisis first attested 1970.
enervate (v.) Look up enervate at Dictionary.com
c. 1600, "deprive of force or strength," from Latin enervatus, past participle of enervare "to weaken" (see enervation). Literal sense of "to weaken, impair" in English is from 1610s. Related: Ennervated; ennervating. As a verb Middle English had enerve (c. 1400, eneruyd).
enervation (n.) Look up enervation at Dictionary.com
early 15c., "impairment, infringement," from Middle French énervation, from Late Latin enervationem (nominative enervatio), noun of action from past participle stem of Latin enervare "weaken," literally "cut the sinews of," from ex- "out" (see ex-) + nervus "sinew" (see nerve (n.)). Figurative sense is from 1550s.
enfant terrible (n.) Look up enfant terrible at Dictionary.com
1851, French, literally "terrible child" (see infant + terrible). One whose unorthodox or shocking speech or manners embarrass his associates as a naughty child embarrasses his elders. French also has enfant gâté, "spoiled child," hence "person given excessive adulation."
enfeeble (v.) Look up enfeeble at Dictionary.com
"to cause to weaken, deprive of strength," mid-14c., from Old French enfeblir "become weak," from en- (see en- (1)) + feble (see feeble). Related: Enfeebled; enfeebling; enfeeblement.
enfeoff (v.) Look up enfeoff at Dictionary.com
c. 1400, based on Old French enfeffer, from en- "in" (see en- (1)) + feoff, variant of fief (n.). Related: Enfeoffment.
Enfield (n.) Look up Enfield at Dictionary.com
type of rifle, 1854, named for government works in Enfield, Middlesex, England, where it was manufactured.
enfilade (n.) Look up enfilade at Dictionary.com
1706, a string of things in a straight line, from French enfilade, from Old French enfiler (13c.) "to thread (a needle) on a string; pierce from end to end," from en- "put on" (see en- (1)) + fil "thread" (see file (v.1)). Used of rows of apartments and lines of trees before military sense came to predominate: "a firing with a straight passage down ranks of men, channels in fortifications, etc." (1796). As a verb from 1706 in the military sense, "rake with shot through the full length." Related: Enfiladed; enfilading. The Old French verb was borrowed in Middle English as enfile "to put (something) on a thread or string."
enflame (v.) Look up enflame at Dictionary.com
mid-14c.; see inflame. Related: Enflamed; enflaming.
enfold (v.) Look up enfold at Dictionary.com
also infold, early 15c., from en- (1) "make, put in" + fold (n.). Related: Enfolded; enfolding.
enforce (v.) Look up enforce at Dictionary.com
mid-14c., "to drive by physical force; to try, attempt, strive; to fortify, strengthen a place;" late 14c. as "exert force, compel; make stronger, reinforce; strengthen an argument; grow stronger, become violent," from Old French enforcier "strengthen, reinforce; use force (on), offer violence (to); oppress; violate, rape" (12c.) or a native formation from en- (1) "make, put in" + force (n.). Meaning "compel obedience to (a law, etc.) is from 1640s. Related: Enforced; enforcing.
enforceable (adj.) Look up enforceable at Dictionary.com
1580s, from enforce + -able. Related: Enforceability (1851).
enforcement (n.) Look up enforcement at Dictionary.com
late 15c., "constraint, compulsion," from Old French enforcement "strengthening, fortification; rape; compulsion, coercion;" from enforcier; see enforce + -ment. Meaning "compelling of obedience to a law, etc." is from 1680s.
enforcer (n.) Look up enforcer at Dictionary.com
1570s, "one who compels, constrains, or urges," agent noun from enforce. Underworld slang meaning "violent intimidator" is from 1934, U.S. underworld slang.
enfranchise (v.) Look up enfranchise at Dictionary.com
early 15c., "grant (someone) the status or privilege of citizenship, admit to membership in a town," from Old French enfranchiss-, present participle stem of enfranchir "to set or make free; grant a franchise to;" from en- "make, put in" (see en- (1)) + franc "free" (see franchise (n.)). Generally with reference to voting privileges after c. 1700. Related: Enfranchised; enfranchisement.
engage (v.) Look up engage at Dictionary.com
early 15c., "to pledge" (something, as security for payment), from Old French engagier "bind (by promise or oath), pledge; pawn" (12c.), from phrase en gage "under pledge," from en "in" (see en- (1)) + gage "pledge," through Frankish from Proto-Germanic *wadiare "pledge" (see wed). It shows the common evolution of Germanic -w- to central French -g- (see gu-). Meaning "attract and occupy the attention of" is from 1640s; that of "employ, secure for aid, employment or use" is from 1640s, from notion of "binding as by a pledge;" meaning "enter into combat or contest with" is from 1640s. Specific sense of "promise to marry" is 1610s (implied in engaged). Machinery sense is from 1884. Also from the French word are German engagiren, Dutch engageren, Danish engagere.
engaged (adj.) Look up engaged at Dictionary.com
"affianced, betrothed," 1610s, past participle adjective from engage. Of telephone lines from 1891.
engagement (n.) Look up engagement at Dictionary.com
1620s, "formal promise," from engage + -ment. Meaning "a battle or fight between armies or fleets" is from 1660s; sense of "state of having entered into a promise of marriage" is from 1742; meaning "appointment" is from 1806. Engagement ring attested by 1863.
engaging (adj.) Look up engaging at Dictionary.com
"interesting, winning, attractive," 1670s, present participle adjective from engage. Related: Engagingly.
engender (v.) Look up engender at Dictionary.com
early 14c., "beget, procreate," from Old French engendrer (12c.) "give birth to, beget, bear; cause, bring about," from Latin ingenerare "to implant, engender, produce," from in- "in" (see in- (2)) + generare "beget, create" (see generation). With euphonious -d- in French. Also from early 14c. engendered was used in a theological sense, with reference to Jesus, "derived (from God)." Meaning "cause, produce" is mid-14c. Related: Engendering.
engine (n.) Look up engine at Dictionary.com
c. 1300, "mechanical device," especially one used in war; "manner of construction," also "skill, craft, innate ability; deceitfulness, trickery," from Old French engin "skill, wit, cleverness," also "trick, deceit, stratagem; war machine" (12c.), from Latin ingenium "inborn qualities, talent" (see ingenious), in Late Latin "a war engine, battering ram" (Tertullian, Isidore of Seville). Sense of "device that converts energy to mechanical power" is 18c.; in 19c. especially of steam engines. Middle English also had ingeny (n.) "gadget, apparatus, device," directly from Latin ingenium.
engineer (n.) Look up engineer at Dictionary.com
mid-14c., enginour, "constructor of military engines," from Old French engigneor "engineer, architect, maker of war-engines; schemer" (12c.), from Late Latin ingeniare (see engine); general sense of "inventor, designer" is recorded from early 15c.; civil sense, in reference to public works, is recorded from c. 1600 but not the common meaning of the word until 19c (hence lingering distinction as civil engineer). Meaning "locomotive driver" is first attested 1832, American English. A "maker of engines" in ancient Greece was a mekhanopoios.
engineer (v.) Look up engineer at Dictionary.com
1818, "act as an engineer," from engineer (n.). Figurative sense of "arrange, contrive, guide or manage (via ingenuity or tact)" is attested from 1864, originally in a political context. Related: Engineered. Middle English had a verb engine "contrive, construct" (late 14c.), also "seduce, trick, deceive" (c. 1300) and "put to torture."
engineering (n.) Look up engineering at Dictionary.com
1720, "work done by an engineer," from engineer (n.). As a field of study, attested from 1792. An earlier word was engineership (1640s); engineery was attempted in 1793, but it did not stick.