Online Etymology Dictionary

Falangist (n.): 1937, member of the Falange, the fascist party in Spain (founded 1933), from Spanish Falange (Española) "(Spanish) Phalanx," from Latin phalanx (genitive phalangis); see phalanx.
Falasha (n.): "dark-skinned Jewish tribe of Abyssinia," 1710, from Ethiopian, literally "exiled, wanderer, immigrant," from falasa "he wandered."
falcate (adj.): 1826, from Latin falcatus, from falcem (nominative falx) "sickle."
falchion (n.): "broad sword, somewhat curved," c.1300, fauchoun, from Old French fauchon, from Vulgar Latin *falcionem, from diminutive of Latin falx "sickle."
falcon (n.): mid-13c., from Old French faucon (12c.), from Late Latin falconem (nominative falco) "falcon," probably from Latin falx (genitive falcis) "curved blade, pruning hook, sickle;" the bird said to be so called for the shape of its talons, legs, or beak, but also possibly from the shape of its spread wings.

The other theory is that falx is of Germanic origin and means "gray bird," which is supported by the antiquity of the word in Germanic but opposed by those who point out that falconry by all evidences was imported from the East, and the Germans got it from the Romans, not the other way around.
falconer (n.): late 14c., "one who hunts with falcons" (as a surname from late 12c.), from Old French fauconier (Modern French fauconnier), from faucon (see falcon). Meaning "one who keeps and trains hawks" is from early 15c.
falconry (n.): 1570s, from French fauconnerie, from faucon (see falcon).
falderol (n.): also falderal, folderol, 1701, nonsense refrain in songs; meaning "gewgaw, trifle" is attested from 1820.
fall (v.): Old English feallan (class VII strong verb; past tense feoll, past participle feallen) "to fall; fail, decay, die," from Proto-Germanic *fallanan (cf. Old Frisian falla, Old Saxon fallan, Dutch vallen, Old Norse falla, Old High German fallan, German fallen), from PIE root *pol- "to fall" (cf. Armenian p'ul "downfall," Lithuanian puola "to fall," Old Prussian aupallai "finds," literally "falls upon").

Most of the figurative senses had developed in Middle English. Meaning "to be reduced" (as temperature) is from 1650s. To fall in love is attested from 1520s; to fall asleep is late 14c. Fall through "come to naught" is from 1781. To fall for something is from 1903.
fall (n.): c.1200, "a falling;" see fall (n.). Old English noun form, fealle, meant "snare, trap." Sense of "autumn" (now only in U.S.) is 1660s, short for fall of the leaf (1540s). That of "cascade, waterfall" is from 1570s. Wrestling sense is from 1550s. Of a city under siege, etc., 1580s. Fall guy is from 1906.
fall out (v.): 1570s in the literal sense; military use is from 1832. Meaning "quarrel" is attested from 1560s (to fall out with "quarrel with" is from 1520s).
fallacious (adj.): c.1500, from fallacy (Latin fallacia) + -ous. Related: Fallaciously; fallaciousness.
fallacy (n.): late 15c., "deception, false statement," from Latin fallacia "deception," noun of quality from fallax (genitive fallacis) "deceptive," from fallere "deceive" (see fail (v.)). Specific sense in logic dates from 1550s. An earlier form was fallace (c.1300), from Old French fallace.
fallback (n.): also fall-back; 1767 as a type of chair; 1930 as "a position to be used in an emergency;" from fall (v.) + back (adv.).
fallen (adj.): c.1400, past participle adjective from fall (v.). Used figuratively for "morally ruined" by 1620s. Meaning "those who have died" attested by 1765. Fallen angel is from 1680s; fallen woman by 1820.
fallibility (n.): 1630s; see fallible + -ity.
fallible (adj.): early 15c., from Medieval Latin fallibilis "liable to err, deceitful." literally "that can be deceived," from Latin fallere "deceive" (see fail).
falling (adj.): present participle adjective from fall (v.). Falling star is from 1560s; falling out "disagreement" is from 1560s. Falling evil "epilepsy" is from early 13c.
Fallopian tube (n.): 1706, from Latinized form of the name of Gabriello Fallopio (1523-1562), Italian anatomist who first described them.
fallout (n.): "radioactive particles," 1950, from fall (v.) + out (adv.).
fallow (n.): c.1300, from Old English fealh "fallow land," from Proto-Germanic *falgo (cf. Old High German felga "harrow," German Felge "plowed-up fallow land," East Frisian falge "fallow," falgen "to break up ground"), perhaps from a derivation of PIE root *pel- "to turn," assimilated in English to fallow (adj.) because of the color of plowed earth. Originally "plowed land," then "land plowed but not planted" (1520s). As an adjective, from late 14c.
fallow (adj.): "pale yellow, brownish yellow," Old English fealu "reddish yellow, yellowish-brown, tawny, dusk-colored," from Proto-Germanic *falwa- (cf. Old Saxon falu, Old Norse fölr, Middle Dutch valu, Dutch vaal, Old High German falo, German falb), from PIE *pal-wo- "dark-colored, gray" (cf. Old Church Slavonic plavu, Lithuanian palvas "sallow;" Greek polios, Sanskrit palitah, Welsh llwyd "gray;" Latin pallere "to be pale"), from root *pal- (see pallor). It also forms the root of words for "pigeon" in Greek (peleia), Latin (palumbes), and Old Prussian (poalis).
false (adj.): late 12c., from Old French fals, faus (12c., Modern French faux) "false, fake, incorrect, mistaken, treacherous, deceitful," from Latin falsus "deceived, erroneous, mistaken," past participle of fallere "deceive, disappoint," of uncertain origin (see fail).

Adopted into other Germanic languages (cf. German falsch, Dutch valsch, Danish falsk), though English is the only one in which the active sense of "deceitful" (a secondary sense in Latin) has predominated. False alarm recorded from 1570s. Related: Falsely; falseness.
falsehood (n.): late 13c., falshede, "deceitfulness," also "a lie," from false + -hood.
falseness (n.): c.1300, from false + -ness.
falsetto (n.): "an artificial voice," 1774, Italian, diminutive of falso "false," from Latin falsus (see false).
falsies (n.): "padded brassiere," 1943, from false + -ie.
falsifiable (adj.): 1610s, from falsify + -able. Related: Falsifiability.
falsification (n.): 1560s, from Late Latin falsificationem (nominative falsificatio), noun of action from past participle stem of falsificare (see falsify).
falsify (v.): mid-15c., "to prove false," from Middle French falsifier (15c.), from Late Latin falsificare (see falsify). Meaning "to make false" is from c.1500. Earlier verb was simply falsen (c.1200). Related: Falsified; falsifying.
falsity (n.): 1550s, from Old French fauseté (12c., Modern French fausseté), from Late Latin falsitatem (nominative falsitas), from Latin falsus (see false).
falter (v.): mid-14c., of unknown origin, possibly from a Scandinavian source (cf. Old Norse faltrask "be burdened, hesitate, be troubled"), or a frequentative of Middle English falden "to fold," influenced by fault. Related: Faltered; faltering.
fame (n.): early 13c., "character attributed to someone;" late 13c., "celebrity, renown," from Old French fame "fame, reputation, renown, rumor," from Latin fama "talk, rumor, report, reputation," from PIE root *bha- (2) "to speak, tell, say" (cf. Sanskrit bhanati "speaks;" Latin fari "to say," fabula "narrative, account, tale, story;" Armenian ban, bay "word, term;" Old Church Slavonic bajati "to talk, tell;" Old English boian "to boast," ben "prayer, request;" Greek pheme "talk," phone "voice, sound," phanai "to speak;" Old Irish bann "law").

The goddess Fama was the personification of rumor in Roman mythology. The Latin derivative fabulare was the colloquial word for "speak, talk" since the time of Plautus, whence Spanish hablar.
I've always been afraid I was going to tap the world on the shoulder for 20 years, and when it finally turned around I was going to forget what I had to say. [Tom Waits, "Playboy" magazine interview, March, 1988]
famed (adj.): "much talked about," 1530s, past participle adjective from fame (v.), c.1300, from Old French famer, from fame (see fame (n.)).
familial (adj.): from French familial, from Latin familia (see family). Meaning "hereditary" is from 1900; "family-like" is from 1903.
familiar (adj.): mid-14c., "intimate, very friendly, on a family footing," from Old French famelier, from Latin familiaris "domestic, of a household;" also "familiar, intimate, friendly," dissimilated from *familialis, from familia (see family). The sense gradually broadened. Of things, from late 15c. The noun meaning "demon, evil spirit that answers one's call" is from 1580s.
familiarise (v.): chiefly British English spelling of familiarize; for spelling, see -ize. Related: Familiarised; familiarising.
familiarity (n.): c.1200, from Old French familiarite and directly from Latin familiaritatem (nominative familiaritas) "intimacy, friendship," from familiaris "friendly, intimate" (see familiar). Meaning "undue intimacy" is from late 14c. That of "close acquaintance" is from c.1600.
familiarization (n.): 1755, noun of action from familiarize.
familiarize (v.): c.1600, "to make well known," from familiar + -ize. Related: Familiarized; familiarizing.
familiarly (adv.): c.1400, from familiar + -ly (2).
family (n.): c.1400, "servants of a household," from Latin familia "family servants, domestics;" also "members of a household," including relatives and servants, from famulus "servant," of unknown origin. Ancestral sense is from early 15c.; "household" sense recorded in English from 1540s; main modern sense of "those connected by blood" (whether living together or not) is first attested 1660s.

Replaced Old English hiwscipe. As an adjective meaning "suitable for a family," by 1807. Buzzword family values first recorded 1966. Phrase in a family way "pregnant" is from 1796. Family circle is 1809; family man, one devoted to wife and children, is 1856 (earlier it meant "thief," 1788, from family in a slang sense of "the fraternity of thieves").
famine (n.): mid-14c., from Old French famine "hunger" (12c.), from Vulgar Latin *famina, from Latin fames "hunger, starvation, famine," of unknown origin.
famish (v.): c.1400, famyschen, alteration of famen (late 14c.), a shortening of Old French afamer, from Vulgar Latin *affamare "to bring to hunger," from ad famem, from Latin fames "hunger" (see famine).

Ending changed mid-14c. to -ish under influence of ravish, anguish, etc. The intransitive sense is from 1520s. Related: Famished; famishing.
famous (adj.): late 14c., from Anglo-French famous, Old French fameus (Modern French fameux), from Latin famosus "much talked of, renowned," often "infamous, notorious, of ill repute," from fama (see fame (n.)). A native word for this was Old English namcuð, literally "name-known." Catch phrase famous last words "remark likely to be proved wrong" is first attested 1948.
famously (adv.): 1570s, from famous + -ly (2).
fan (n.1): device to make an air current, Old English fann (West Saxon) "a basket or shovel for winnowing grain" (by tossing it in the air), from Latin vannus, related to ventus "wind" (see wind (n.1)).

The chaff, being lighter, would blow off. Sense of "device for moving air" first recorded late 14c.; the hand-held version is first attested 1550s. A fan-light (1819) was shaped like a lady's fan.
fan (n.2): "devotee," 1889, American English, originally of baseball enthusiasts, probably a shortening of fanatic, but may be influenced by the fancy, a collective term for followers of a certain hobby or sport (especially boxing); see fancy. There is an isolated use from 1682, but the modern word is likely a late 19c. formation. Fan club attested by 1930.
fan (v.): late Old English fannian "to winnow grain," from the noun (see fan (n.1)). Meaning "to stir up air" is from early 15c. Related: Fanned; fanning. To fan out "spread out like a hand-held fan," is from 1590s.
fanatic (n.): 1520s, "insane person," from Latin fanaticus "mad, enthusiastic, inspired by a god," also "furious, mad," originally, "pertaining to a temple," from fanum "temple," related to festus "festive" (see feast). Meaning "zealous person" is mid-17c. As an adjective, in English, 1530s, "furious;" meaning "characterized by excessive enthusiasm," especially in religion (of Nonconformists), is from 1640s.
A fanatic is someone who can't change his mind and won't change the subject. [attributed to Winston Churchill]