frivolity (n.) Look up frivolity at Dictionary.com
1796, from French frivolité, from Old French frivole "frivolous," from Latin frivolus (see frivolous).
frivolous (adj.) Look up frivolous at Dictionary.com
mid-15c., from Latin frivolus "silly, empty, trifling, worthless, brittle," diminutive of *frivos "broken, crumbled," from friare "break, rub away, crumble." Related: Frivolously; frivolousness.
frizz (v.) Look up frizz at Dictionary.com
also friz, 1610s (implied in frizzed), probably from French friser "to curl, dress the hair" (16c.), perhaps from stem of frire "to fry, cook." Assimilated to native frizzle. Related: Frizzed; frizzing. As a noun from 1660s, "frizzed hair."
frizzle (v.) Look up frizzle at Dictionary.com
"curl hair," 1560s, perhaps related to Old English fris "curly" and Old Frisian frisle. Or else from Middle French friser "to curl" (see frizz (v.)). Related: Frizzled; frizzling. As a noun from 1610s, "crisp curl," from the verb.
frizzy (adj.) Look up frizzy at Dictionary.com
1870, from frizz + -y (2). Related: Frizziness.
fro Look up fro at Dictionary.com
"away, backwards," c.1200, North English and Scottish dialectal fra, Midlands dialect fro, from Old Norse fra "from" (see from).
frock (n.) Look up frock at Dictionary.com
mid-14c., from Old French froc "a monk's habit" (12c.), of unknown origin; perhaps from Frankish *hrok or some other Germanic source (compare Old High German hroc "mantle, coat;" Old Norse rokkr, Old English rocc, Old Frisian rokk, German Rock "coat"), from PIE root *rug- "to spin."

Another theory traces it to Medieval Latin floccus, from Latin floccus "flock of wool." Meaning "outer garment for women or children" is from 1530s. Frock-coat attested by 1823.
frog (n.1) Look up frog at Dictionary.com
Old English frogga, a diminutive of frox, forsc, frosc "frog," from Proto-Germanic *fruska-z (cognates: Old Norse froskr, Middle Dutch vorsc, German Frosch "frog"), probably literally "hopper," from PIE root *preu- "to hop" (cognates: Sanskrit provate "hops," Russian prygat "to hop, jump").

The Latin word (rana) is imitative of croaking. Collateral Middle English forms frude, froud are from Old Norse frauðr "frog," and frosk "frog" survived in English dialects into the 19c.
I always eat fricasseed frogs regretfully; they remind one so much of miniature human thighs, and make one feel cannibalistic and horrid .... [H. Ellen Brown, "A Girl's Wanderings in Hungary," 1896]
As a derogatory term for "Frenchman," 1778 (short for frog-eater), but before that (1650s) it meant "Dutch" (from frog-land "marshy land"). To have a frog in the throat "be hoarse" is from 1892, from the "croaking" sound.
frog (n.2) Look up frog at Dictionary.com
fastening for clothing, 1719, originally a belt loop for carrying a weapon, of unknown origin; perhaps from Portuguese froco, from Latin floccus "flock of wool."
frog march Look up frog march at Dictionary.com
also frog-march, 1871, a term that originated among London police and referred to their method of moving "a drunken or refractory prisoner" by carrying him face-down between four people, each holding a limb; the connection with frog (n.1) perhaps being the notion of going along belly-down. By the 1930s, the verb was used in reference to the much more efficient (but less frog-like) method of getting someone in an arm-behind-the-back hold and hustling him or her along like that.
froggy (adj.) Look up froggy at Dictionary.com
1610s, "full of frogs," from frog (n.1) + -y (2). Meaning "frog-like" is from 1837. As a disparaging term for a Frenchman, from 1872. Related: Frogginess.
frogman (n.) Look up frogman at Dictionary.com
"scuba diver in rubber suit," 1945, from frog (n.1) + man (n.).
frolic Look up frolic at Dictionary.com
1530s, as an adjective, "joyous, merry," from Middle Dutch vrolyc (adj.) "happy," from vro- "merry, glad" + lyc "like" (see like (adj.)). Cognate with German fröhlich "happy." The stem is cognate with Old Norse frar "swift," Middle English frow "hasty," from PIE *preu- (see frog (n.1)), giving the whole an etymological sense akin to "jumping for joy." The verb is first attested 1580s. Related: Frolicked; frolicking. As a noun, from 1610s.
frolicsome (adj.) Look up frolicsome at Dictionary.com
1690s, from frolic + -some (1).
from (prep.) Look up from at Dictionary.com
Old English fram "from, since, by, as a result," originally "forward movement, advancement," evolving into sense of "movement away," from Proto-Germanic *fr- (cognates: Old Saxon, Old High German, Gothic fram "from, away," Old Norse fra "from," fram "forward"), corresponding to PIE *pro (see pro-).
fromage (n.) Look up fromage at Dictionary.com
French for "cheese," from French fromage, formage (13c.), from Medieval Latin formaticum (source also of Italian formaggio), a derivation from Latin forma "shape, form, mold" (cf Medieval Latin casei forma; see form (v.)).
fromward Look up fromward at Dictionary.com
Old English framweard "about to depart; doomed to die; with back turned;" see froward.
frond (n.) Look up frond at Dictionary.com
1785, from Latin frons (genitive frondis) "leafy branch, green bough, foliage." Adopted by Linnæus in a sense distinct from folium.
Fronde (n.) Look up Fronde at Dictionary.com
1798, from French fronde (14c.), "sling," from Old French fonde, from Latin funda "casting net," of unknown origin.

Name given to the party which rose against Mazarin and the court during the minority of Louis XIV, supposedly from the use of stone-casting slings to attack property of their opponents. Hence, sometimes used figuratively for "violent political opposition."
front (n.) Look up front at Dictionary.com
late 13c., "forehead," from Old French front "forehead, brow" (12c.), from Latin frontem (nominative frons) "forehead, brow, front; facade, forepart; appearance," perhaps literally "that which projects," from PIE *bhront-, from root *bhren- "to project, stand out." Or from PIE *ser- (4), "base of prepositions and preverbs with the basic meaning 'above, over, up, upper'" [Watkins, not in Pokorny].

Sense of "foremost part of anything" developed in Latin. The military sense of "foremost part of an army" (mid-14c.) led to the meaning "field of operations in contact with the enemy" (1660s). Home front is from 1919. Sense of "public facade" is from 1891; that of "something serving as a cover for illegal activities" is from 1905. Meteorological sense first recorded 1921. Front yard first attested 1767.
front (v.) Look up front at Dictionary.com
1520s, from Middle French fronter, from Old French front (see front (n.)). Related: Fronted; fronting.
frontage (n.) Look up frontage at Dictionary.com
1620s, from front (n.) + -age.
frontal (adj.) Look up frontal at Dictionary.com
1650s, of the forehead; 1971 with reference to the naked body; from Modern Latin frontalis, from front-, stem of frons "brow, forehead" (see front). Or in some cases probably from front (n.) + adjectival suffix -al (1).
frontier (n.) Look up frontier at Dictionary.com
c.1400, from Old French frontier "prow of a ship, front rank of an army" (13c.), noun use of adjective frontier "facing, neighboring," from front "brow" (see front (n.)).

Originally the front line of an army, sense of "borderland" is first attested early 15c. In reference to North America, from 1670s; later with a specific sense:
What is the frontier? ... In the census reports it is treated as the margin of that settlement which has a density of two or more to the square mile. [F.J. Turner, "The Frontier in American History," 1920]
Frontiersman is from 1782.
frontispiece (n.) Look up frontispiece at Dictionary.com
1590s, "decorated entrance of a building," from Middle French frontispice, probably from Italian frontespizio and Late Latin frontispicium "facade," originally "a view of the forehead, judgment of character through facial features," from Latin frons (genitive frontis) "forehead" (see front (n.)) + specere "to look at" (see scope (n.1)). Sense of "illustration facing a book's title page" first recorded 1680s. The spelling alteration is apparently from confusion with piece.
frontlet (n.) Look up frontlet at Dictionary.com
from Old French frontelet, diminutive of frontel (Modern French fronteau) "forehead, front of a helmet, hairband," from Late Latin frontale "an ornament for the forehead," from frons (see front (n.)).
frontline Look up frontline at Dictionary.com
also front-line, 1899 (n.), 1915 (adj.), from front (adj.) + line (n.).
frontrunner (n.) Look up frontrunner at Dictionary.com
also front-runner, of political candidates, 1908, American English, a metaphor from horse racing (where it is used by 1903 of a horse that runs best while in the lead).
frore (adj.) Look up frore at Dictionary.com
"frosty, frozen," archaic (but found in poetry as late as Keats), from Old English froren, past participle of freosan (see freeze (v.)).
frosh (n.) Look up frosh at Dictionary.com
student colloquial shortening and alteration of freshman, attested by 1915, "perh. under influence of German frosch frog, (dial.) grammar-school pupil" [OED].
frost (n.) Look up frost at Dictionary.com
Old English forst, frost "a freezing, becoming frozen, extreme cold," from Proto-Germanic *frusta- (cognates: Old Saxon, Old Frisian, Old High German frost, Middle Dutch and Dutch vorst), related to freosan "to freeze," from PIE *preus- "to freeze; burn" (see freeze (v.)). Both forms of the word were common in English till late 15c.; the triumph of frost may be due to its similarity to the forms in other Germanic languages.
frost (v.) Look up frost at Dictionary.com
1630s, from frost (n.). Related: Frosted; frosting.
frostbite (n.) Look up frostbite at Dictionary.com
also frost-bite, 1813, from frost (n.) + bite (n.).
frostbitten (adj.) Look up frostbitten at Dictionary.com
also frost-bitten, 1550s, from frost (n.) + bitten.
frosted (adj.) Look up frosted at Dictionary.com
1640s of whitening hair; 1680s of glass; 1734 of sugar or icing, past participle adjective from frost.
frosting (n.) Look up frosting at Dictionary.com
1610s as an action; 1756 as a substance; meaning "cake icing" is from 1858; verbal noun from frost (v.).
frosty (adj.) Look up frosty at Dictionary.com
Old English forstig, fyrstig (cognates: Dutch vorstig, German frostig); see frost (n.) + -y (2). Figurative use from late 14c. Related: Frostily; frostiness.
froth (n.) Look up froth at Dictionary.com
c.1300, from an unrecorded Old English word, or else from Old Norse froða "froth," from Proto-Germanic *freuth-. Old English had afreoðan "to froth," from the same root. The modern derived verb is from late 14c. Related: Frothed; frothing.
frothy (adj.) Look up frothy at Dictionary.com
1530s, from froth + -y (2). Related: Frothiness.
frottage (n.) Look up frottage at Dictionary.com
1933, from French frottage "rubbing, friction," from frotter "to rub," from Old French froter "to rub, wipe; beat, thrash" (12c.), from Latin fricare "to rub" (see friction). As a paraphilia, it is known as frotteurism.
frou-frou Look up frou-frou at Dictionary.com
1870, "a rustling," from French (19c.), possibly imitative of the rustling of a dress. Meaning "fussy details" is from 1876.
frounce (v.) Look up frounce at Dictionary.com
c.1300, "to gather in folds," from Old French froncier, from fronce (n.), of unknown origin. Related: Frounced; frouncing.
frow (n.) Look up frow at Dictionary.com
"Dutchwoman," late 14c., from Middle Dutch vrouwe (Dutch vrow), cognate with German Frau (see frau).
froward (adv.) Look up froward at Dictionary.com
Old English fromweard "turned from or away," from from + -weard (see -ward). Opposite of toward, it renders Latin pervertus in early translations of the Psalms, and also meant "about to depart, departing," and "doomed to die." Related: Frowardly; frowardness.
frown (v.) Look up frown at Dictionary.com
late 14c., from Old French frognier "to frown or scowl, snort, turn one's nose up," related to froigne "scowling look," probably from Gaulish *frogna "nostril" (compare Welsh ffroen "nose"), with a sense of "snort," or perhaps "haughty grimace." Related: Frowned; frowning.
frown (n.) Look up frown at Dictionary.com
1580s, from frown (v.).
frowsty (adj.) Look up frowsty at Dictionary.com
"having an unpleasant smell," 1865, of unknown origin; perhaps related to Old French frouste "ruinous, decayed," or to Old English þroh "rancid;" both of which also are of uncertain origin.
frowzy (adj.) Look up frowzy at Dictionary.com
also frowsy, 1680s, possibly related to dialectal frowsty (q.v.).
frozen (adj.) Look up frozen at Dictionary.com
mid-14c., past participle adjective from freeze (v.). Figurative use is from 1570s. Of assets, bank accounts, etc., from 1922.
fructify (v.) Look up fructify at Dictionary.com
early 14c., from Old French fructifiier (12c.) "bear fruit, grow, develop," from Late Latin fructificare "bear fruit," from Latin fructus (see fruit) + root of facere "make" (see factitious). Related: Fructified; fructifying.