conjecture (v.) Look up conjecture at Dictionary.com
early 15c., from conjecture (n.). In Middle English also with a parallel conjecte (n.), conjecten (v.). Related: Conjectured; conjecturing.
conjecture (n.) Look up conjecture at Dictionary.com
late 14c., "interpretation of signs and omens," from Old French conjecture "surmise, guess," or directly from Latin coniectura "conclusion, interpretation, guess, inference," literally "a casting together (of facts, etc.)," from coniectus, past participle of conicere "to throw together," from com- "together" (see com-) + iacere "to throw" (from PIE root *ye- "to throw, impel"). Sense of "forming of opinion without proof" is 1530s.
conjoin (v.) Look up conjoin at Dictionary.com
late 14c., from Old French conjoindre "meet, come together" (12c.), from Latin coniungere "to join together," from com "with, together" (see com-) + iungere "to join together" (from nasalized form of PIE root *yeug- "to join"). Related: Conjoined, conjoining.
conjoint (adj.) Look up conjoint at Dictionary.com
late 14c., from Middle French conjoint, past participle of conjoindre (see conjoin). Related: Conjointly (early 14c.).
conjugal (adj.) Look up conjugal at Dictionary.com
1540s, from Middle French conjugal (13c.), from Latin coniugalis "relating to marriage," from coniunx (genitive coniugis) "spouse," related to coniugare "to join together," from com "with, together" (see com-) + iugare "to join," from iugum "yoke" (from PIE root *yeug- "to join").
conjugate (v.) Look up conjugate at Dictionary.com
1520s, in grammatical sense; 1560s in literal sense, from Latin coniugatus, past participle of coniugare "to yoke together," from com "with, together" (see com-) + iugare "to join," from iugum "yoke" (from PIE root *yeug- "to join"). Earlier as an adjective (late 15c.). Related: Conjugated; conjugating.
conjugation (n.) Look up conjugation at Dictionary.com
mid-15c., from Latin coniugationem (nominative coniugatio) "a combining, connecting," noun of action from coniugare "to join together," from com "with, together" (see com-) + iugare "to join," from iugum "yoke" (from PIE root *yeug- "to join"). Grammatical sense is 1520s.
conjunct (adj.) Look up conjunct at Dictionary.com
mid-15c., from Latin coniunctus, past participle of coniugare "to join together," from com "with, together" (see com-) + iugare "to join," from iugum "yoke" (from PIE root *yeug- "to join"). A doublet of conjoint.
conjunction (n.) Look up conjunction at Dictionary.com
late 14c., originally of planets, from Old French conjonction "union, joining, sexual intercourse" (12c.), from Latin coniunctionem (nominative coniunctio), from past participle stem of coniugare "join together" (see conjugal). Compare Italian congiunzione, Spanish conjunción. Grammatical sense (late 14c.) was in Latin, a loan-translation of Greek syndesmos. The word also had the meaning "sexual union" 17c.-18c.
conjunctiva (n.) Look up conjunctiva at Dictionary.com
1540s, medical Latin, short for membrana conjunctiva "conjunctive membrane" (see conjunctive).
conjunctive (adj.) Look up conjunctive at Dictionary.com
late 15c., from Latin coniunctivus "serving to connect," from coniunctus, past participle of coniungere (see conjoin). Grammatical sense is from 1660s.
conjunctivitis (n.) Look up conjunctivitis at Dictionary.com
1835, inflammation of the conjunctiva; from conjunctiva + -itis "inflammation."
conjuncture (n.) Look up conjuncture at Dictionary.com
c. 1600, from French conjoncture (16c.), from Modern Latin *conjunctura, from Latin coniunctus (see conjunct).
conjuration (n.) Look up conjuration at Dictionary.com
late 14c., coniuracioun, "conspiracy" (now obsolete), also "a calling upon something supernatural," from Old French conjuracion "spell, incantation, formula used in exorcism," from Latin coniurationem (nominative coniuratio) "a swearing together, conspiracy," noun of action from coniurare "to swear together; conspire," from com- "together" (see com-) + iurare "to swear" (see jury (n.)).
conjure (v.) Look up conjure at Dictionary.com
late 13c., "command on oath," from Old French conjurer "invoke, conjure" (12c.), from Latin coniurare "to swear together; conspire," from com- "together" (see com-) + iurare "to swear" (see jury (n.)). Magical sense is c. 1300, for "constraining by spell" a demon to do one's bidding. Related: Conjured; conjuring. Phrase conjure up "cause to appear in the mind" (as if by magic) attested from 1580s.
conjurer (n.) Look up conjurer at Dictionary.com
late 14c., from Anglo-French conjurour, Old French conjureur "conjurer, magician, exorcist," from Latin coniurator, from coniurare (see conjure).
conk (v.) Look up conk at Dictionary.com
as in conk out, 1918, coined by World War I airmen, perhaps in imitation of the sound of a stalling motor, reinforced by conk (v.) "hit on the head," originally "punch in the nose" (1821), from conk (n.), slang for "nose" (1812), perhaps from fancied resemblance to a conch (pronounced "conk") shell.
conker (n.) Look up conker at Dictionary.com
"snail shell," also "horse chestnut," from children's game of conkers (q.v.).
conkers (n.) Look up conkers at Dictionary.com
"child's game played with horse chestnuts," originally with snail shells, 1847, probably a variant of conquer. The goal was to break the other player's item by hitting it with yours.
conlang (n.) Look up conlang at Dictionary.com
by 1991, from constructed language.
connate (adj.) Look up connate at Dictionary.com
1640s, from Late Latin connatus "born together, twins," past participle of connasci "to be born together," from assimilated form of com "with, together" (see com-) + nasci "to be born" (Old Latin gnasci, from PIE root *gene- "give birth, beget"). Related: Connation.
connect (v.) Look up connect at Dictionary.com
mid-15c., from Latin conectere "join together," from assimilated form of com "together" (see com-) + nectere "to bind, tie" (from PIE root *ned- "to bind, tie"). Displaced 16c. by connex (1540s), from Middle French connexer, from Latin *connexare, a supposed frequentative of conectere (past participle stem connex-). Connect was re-established 1670s.

A similar change took place in French, where connexer was superseded by connecter. Meaning "to establish a relationship" (with) is from 1881. Slang meaning "get in touch with" is attested by 1926, from telephone connections. Meaning "awaken meaningful emotions, establish rapport" is from 1942. Of a hit or blow, "to reach the target," from c. 1920. Related: Connected; connecting; connectedness.
Connecticut Look up Connecticut at Dictionary.com
U.S. state, originally the name of the river, said to be from Mohican (Algonquian) quinnitukqut "at the long tidal river," from *kwen- "long" + *-ehtekw "tidal river" + *-enk "place."
connection (n.) Look up connection at Dictionary.com
Middle English conneccion (late 14c.), also connexioun (mid-15c.), from Old French connexion, from Latin connexionem (nominative connexio) "a binding or joining together," from *connexare, frequentative of conectere "to fasten together, to tie, join together," from assimilated form of com "together" (see com-) + nectere "to bind, tie" (from PIE root *ned- "to bind, tie").

Spelling shifted from connexion to connection (especially in American English) mid-18c. under influence of connect, abetted by affection, direction, etc. See -xion.
connective (adj.) Look up connective at Dictionary.com
1650s, from connect + -ive (if from Latin, it likely would have been *connexive). Connective tissue is from 1839.
connectivity (n.) Look up connectivity at Dictionary.com
1872, from connective + -ity.
connector (n.) Look up connector at Dictionary.com
1795, "tube for connecting other materials," agent noun in Latin form from connect and usefully distinct from connecter.
connexion (n.) Look up connexion at Dictionary.com
see connection; also see -xion.
conniption (n.) Look up conniption at Dictionary.com
1833, American English, origin uncertain; perhaps related to corruption, which was used in a sense of "anger" from 1799, or from English dialectal canapshus "ill-tempered, captious," probably a corruption of captious.
connivance (n.) Look up connivance at Dictionary.com
the main modern form of connivence (q.v.).
connive (v.) Look up connive at Dictionary.com
c. 1600, from Latin connivere, also conivere "to wink," hence, "to wink at (a crime), be secretly privy," from com- "together" (see com-) + base akin to nictare "to wink," from PIE root *kneigwh- (see nictitate). Related: Connived; conniving.
connivence (n.) Look up connivence at Dictionary.com
1590s, from Latin conniventia, from conniventem (nominative connivens), present participle of connivere "to wink," hence, "to wink at (a crime), be secretly privy" (see connive). Spelling with -a- prevailed after early 18c. but is unetymological.
connivent (adj.) Look up connivent at Dictionary.com
1640s, from Latin conniventem (nominative connivens), present participle of connivere "to wink," hence, "to wink at (a crime), be secretly privy" (see connive).
conniving (adj.) Look up conniving at Dictionary.com
1783, present participle adjective from connive. Earlier in this sense was connivent.
connoisseur (n.) Look up connoisseur at Dictionary.com
1714, from French connoisseur (Modern French connaiseur), from Old French conoisseor "an expert, a judge, one well-versed," from conoistre "to know," from Latin cognoscere "to get to know, recognize, become well-acquainted with," from com "with, together" (see com-) + gnoscere "recognize," from PIE root *gno- "to know."
Connor Look up Connor at Dictionary.com
masc. proper name, little used in U.S. before 1980; in the top 100 names given to boys from 1992; apparently an alteration and appropriation of the surname Conner (13c.), representing Old English cunnere "examiner, inspector" (as in ale-conner; see con (n.2)).
connotate (v.) Look up connotate	 at Dictionary.com
1590s, from Medieval Latin connotatus, past participle of connotare "signify in addition to the main meaning," a term in logic (see connotation). Obsolete; replaced by connote.
connotation (n.) Look up connotation at Dictionary.com
1530s, from Medieval Latin connotationem (nominative connotatio), from connotat-, past participle stem of connotare "signify in addition to the main meaning," a term in logic, literally "to mark along with," from Latin com "with, together" (see com-) + notare "to mark, note, make a note," from nota "mark, sign, means of recognition" (see note (n.)).

A word denotes its primary meaning, its barest adequate definition -- father denotes "one that has begotten." A word connotes the attributes commonly associated with it -- father connotes "male sex, prior existence, greater experience, affection, guidance."
connote (v.) Look up connote at Dictionary.com
1660s, from Medieval Latin connotare "to mark along with," (see connotation). A common word in medieval logic. Related: Connoted; connoting.
connubial (adj.) Look up connubial at Dictionary.com
1650s, from Latin connubialis, variant of conubialis "pertaining to wedlock," from conubium "marriage," from com "with, together" (see com-) + nubere "to wed" (see nuptial).
conquer (v.) Look up conquer at Dictionary.com
c. 1200, cunquearen, from Old French conquerre "conquer, defeat, vanquish," from Vulgar Latin *conquaerere (for Latin conquirere) "to search for, procure by effort, win," from Latin com-, intensive prefix (see com-), + quaerere "to seek, gain" (see query (v.)). Related: Conquered; conquering.
conquerer (n.) Look up conquerer at Dictionary.com
obsolete form of conqueror; see -er.
conqueror (n.) Look up conqueror at Dictionary.com
c. 1300, from Anglo-French conquerour, Old French conquereor, from Old French conquerre (see conquer). Another early form was conquestor. William the Conqueror so called from early 12c. in Anglo-Latin: Guillelmus Magus id est conquæstor rex Anglorum.
conquest (n.) Look up conquest at Dictionary.com
early 14c., a merged word from Old French conquest "acquisition" (Modern French conquêt), and Old French conqueste "conquest, acquisition" (Modern French conquête), both from past participle of conquerre, from Vulgar Latin *conquaerere (see conquer).
conquistador (n.) Look up conquistador at Dictionary.com
1830, from Spanish conquistador, literally "conqueror," noun of action from conquistar "to conquer," from Vulgar Latin conquistare, from Latin conquistus, past participle of conquirere "to seek for" (see conquer).
Conrad Look up Conrad at Dictionary.com
masc. proper name, from Old High German Kuonrat, literally "bold in counsel," from kuon "bold" + rat "counsel" (see read (v.)).
consanguine (adj.) Look up consanguine at Dictionary.com
c. 1600, from French consanguin (14c.), from Latin consanguineus "of the same blood" (see consanguinity).
consanguineous (adj.) Look up consanguineous at Dictionary.com
c. 1600, from Latin consanguineus "of the same blood" (see consanguinity).
consanguinity (n.) Look up consanguinity at Dictionary.com
c. 1400, from Middle French consanguinité, from Latin consanguinitatem (nominative consanguinitas), from consanguineus "consanguineous, of the same blood," from com "with, together" (see com-) + sanguineus "of blood" (see sanguine).
conscience (n.) Look up conscience at Dictionary.com
early 13c., from Old French conscience "conscience, innermost thoughts, desires, intentions; feelings" (12c.), from Latin conscientia "knowledge within oneself, sense of right, a moral sense," from conscientem (nominative consciens), present participle of conscire "be (mutually) aware," from com- "with," or "thoroughly" (see com-) + scire "to know" (see science).

Probably a loan-translation of Greek syneidesis, literally "with-knowledge." Sometimes nativized in Old English/Middle English as inwit. Russian also uses a loan-translation, so-vest, "conscience," literally "with-knowledge."