Online Etymology Dictionary

fraternally (adv.): 1610s, from fraternal + -ly (2).
fraternity (n.): early 14c., "body of men associated by common interest," from Old French fraternité (12c.), from Latin fraternitatem (nominative fraternitas) "brotherhood," from fraternus "brotherly," from frater "brother," from PIE *bhrater (see brother). Meaning "state or condition of being as brothers" is from late 15c. College Greek-letter organization sense is from 1777, first in reference to Phi Beta Kappa.
fraternization (n.): 1792, "act of uniting as brothers," from French fraternization (see fraternity); of relations between occupying soldiers and occupied civilians, from mid-19c; explicitly from 1944 (see fraternize).
fraternize (v.): 1610s, "to sympathize as brothers," from French fraterniser, from Medieval Latin fraternizare, from fraternus "brotherly" (see fraternity). Military sense of "cultivate friendship with enemy troops" is from 1897 (used in World War I with reference to the Christmas Truce). Used oddly by World War II armed forces to mean "have sex with women from enemy countries."
A piece of frat, Wren-language for any attractive young woman -- ex-enemy -- in occupied territory. [John Irving, "Royal Navalese," 1946]
Related: Fraternized; fraternizing.
fratricidal (adj.): 1804, from fratricide + -al (1).
fratricide (n.): mid-15c., "person who kills a brother;" 1560s, "act of killing a brother," from Latin fratricida "brother-slayer," from frater "brother" (see brother) + cida "killer," or cidum "a killing," both from caedere "to kill, to cut down" (see -cide). Among several Old English words for this were broðorbana "one who kills a brother;" broðorcwealm "act of killing a brother."
frau (n.): "married woman," 1813, from German Frau "woman, wife," from Middle High German vrouwe "lady, mistress," from Old High German frouwa "mistress, lady" (9c.), from Proto-Germanic *frowo- "lady," fem. of *frawan "lord," from PIE root *per- (1) "beyond, forward," in extended senses "chief, first" (see per).
fraud (n.): "criminal deception," early 14c., from Old French fraude "deception, fraud" (13c.), from Latin fraudem (nominative fraus) "deceit, injury." The noun meaning "impostor, humbug" is attested from 1850. Pious fraud "deception practiced for the sake of what is deemed a good purpose" is from 1560s.
fraudster (n.): 1975, from fraud + -ster. Earlier words were fraudsman (1610s); frauditor (1550s).
fraudulent (adj.): early 15c., from Middle French fraudulent, from Latin fraudulentus "cheating, deceitful," from fraus (see fraud). Related: Fraudulently.
frauendienst (n.): "excessive chivalry toward women," from the title of a work by Ulrich von Lichtenstein (13c.), from German frauen, plural of frau + dienst "service."
fraught (v.): early 14c., "laden" (of vessels), past participle of Middle English fraughten "to load (a ship) with cargo," from fraght "cargo, lading of a ship" (early 13c.), variant of freight; influenced by Middle Dutch vrachten "to load or furnish with cargo," from Proto-Germanic *fra-aihtiz (see freight (n.)). Figurative sense is first attested 1570s.
fraulein (n.): German Fräulein "unmarried woman" (Middle High German vrouwelin), diminutive of Frau "lady" (see frau).
fray (n.): mid-14c., "feeling of alarm," shortening of affray (q.v.; see also afraid). Meaning "a brawl, a fight" is from early 15c. (but late 14c. in Anglo-Latin). Fraymaker "fighter, brawler" is an excellent word from a 1530s statute.
fray (v.): "wear out by rubbing," c.1400, from Middle French frayer "to rub against," from Old French froiier "rub, scrape," from Latin fricare "to rub, rub down" (see friction). Related: Frayed; fraying.
frayed (adj.): "worn by rubbing," 1814, past participle adjective from fray (v.).
frazzle (v.): c.1825, "to unravel" (of clothing), from East Anglian variant of 17c. fasel "to unravel, fray" (like the end of a rope), from Middle English facelyn "to fray" (mid-15c.), from fasylle "fringe, frayed edge," diminutive of Old English fæs "fringe."

Cf. German Faser "thread, fiber, filament," Middle Dutch vese "fringe, fiber, chaff." Probably influenced in form by fray (v.). Related: Frazzled. As a noun, from 1865, American English.
freak (n.): 1560s, "sudden turn of mind," of unknown origin, perhaps related to Old English frician "to dance" (not recorded in Middle English, but the word may have survived in dialect) [OED, Barnhart], or perhaps from Middle English frek "bold, quickly," from Old English frec "greedy, gluttonous" (cf. German frech "bold, impudent").

Sense of "capricious notion" (1560s) and "unusual thing, fancy" (1784) preceded that of "strange or abnormal individual" (first in freak of nature, 1847; cf. Latin lusus naturæ, used in English from 1660s). The sense in health freak, ecology freak, etc. is attested from 1908 (originally Kodak freak, a camera buff). Freak show attested from 1887.
freak (v.): "change, distort," 1911, from freak (n.). Earlier, "to streak or fleck randomly" (1630s). Related: Freaked; freaking.
freak out (n.): also freakout "bad psychedelic drug trip or something comparable to one," 1966 (despite an amusing coincidental appearance of the phrase dug up by the OED in "Fanny Hill" from 1749), from verbal phrase freak out, attested from 1965 in the drug sense (from 1902 in a sense "change, distort, come out of alignment"); see freak (n.). Freak (n.) "drug user" is attested from 1945.
She had had her freak out, and had pretty plentifully drowned her curiosity in a glut of pleasure .... [Cleland, "Memoirs of a Woman of Pleasure," 1749]
freakish (adj.): 1650s, "capricious," from freak (n.) + -ish. Meaning "grotesque" is recorded from 1805. Related: Freakishly; freakishness.
freaky (adj.): 1824, from freak (n.) + -y (2). Psychedelic sense is from 1966.
freckle (n.): late 14c., also frecken, probably from Old Norse freknur (plural) "freckles" (cf. Icelandic frekna, Danish fregne, Swedish frägne "freckle"), from PIE *(s)preg- "to jerk, scatter" (see sprout (v.)). Related: Freckles.
freckle (v.): late 14c. (implied in fracled "spotted," from freckle (n.); freckle as a verb is recorded from 1610s. Related: Freckled; freckling.
Freddie Mac: by 1992, vaguely from Federal Home Loan Mortgage Corporation.
Frederick: masc. proper name, from French Frédéric, from German Friedrich, from Old High German Fridurih, from Proto-Germanic *Frid-ric, literally "peace-rule." Not a common name in medieval England, found mostly in the eastern counties.
free (adj.): Old English freo "free, exempt from, not in bondage," also "noble; joyful," from Proto-Germanic *frijaz (cf. Old Frisian fri, Old Saxon and Old High German vri, German frei, Dutch vrij, Gothic freis "free"), from PIE *prijos "dear, beloved," from root *pri- "to love" (cf. Sanskrit priyah "own, dear, beloved," priyate "loves;" Old Church Slavonic prijati "to help," prijatelji "friend;" Welsh rhydd "free").

The primary sense seems to have been "beloved, friend, to love;" which in some languages (notably Germanic and Celtic) developed also a sense of "free," perhaps from the terms "beloved" or "friend" being applied to the free members of one's clan (as opposed to slaves, cf. Latin liberi, meaning both "free" and "children").

Cf. Gothic frijon "to love;" Old English freod "affection, friendship," friga "love," friðu "peace;" Old Norse friðr, German Friede "peace;" Old English freo "wife;" Old Norse Frigg "wife of Odin," literally "beloved" or "loving;" Middle Low German vrien "to take to wife, Dutch vrijen, German freien "to woo."

Of nations, "not subject to foreign rule or to despotism," it is recorded from late 14c. (Free world "non-communist nations" attested from 1950.) Sense of "given without cost" is 1580s, from notion of "free of cost." Free lunch, originally offered in bars to draw in business, by 1850, American English. Free pass on railways, etc., attested by 1850. Free speech in Britain used of a privilege in Parliament since the time of Henry VIII. In U.S., as a civil right, it became a prominent phrase in the debates over the Gag Rule (1836).

Free enterprise recorded from 1890; free trade is from 1823. Free will is from early 13c. Free association in psychology is from 1899. Free love "sexual liberation" attested from 1822. Free range (adj.) is attested by 1960. Free and easy "unrestrained" is from 1690s.
free (v.): Old English freogan "to free, liberate, manumit," also "to love, think of lovingly, honor," from freo (see free (adj.)). Cf. Old Frisian fria "to make free;" Old Saxon friohan "to court, woo;" German befreien "to free," freien "to woo;" Old Norse frja "to love;" Gothic frijon "to love." Related: Freed; freeing.
free verse (n.): 1908; see vers libre.
free-born (adj.): mid-14c., from free (adj.) + born.
free-for-all (n.): "mass brawl" (one in which all may participate), 1881.
free-hand (adv.): of drawing, from 1848; see free (adj.) + hand.
free-spirited (adj.): also freespirited, 1670s, from free (adj.) + spirited.
free-thinker (n.): 1690s, from free (adj.) + agent noun from think.
freebase: 1980 (noun and verb), in reference to cocaine. As a chemical process, it returns a salt form of an alkaloid to its pure form. Related: Freebased; freebasing.
freebie: also freeby, 1942 (adj.); 1946 (n.); perhaps as early as 1900; formed "arbitrarily" [OED] from free (adj.).
freebooter (n.): 1560s, loan-translation of Dutch vrijbuiter "plunderer, robber," from vrijbuiten "to rob, plunder," from vrijbuit "plunder," literally "free booty," from vrij "free" + buit "booty," from buiten "to exchange or plunder," from Middle Dutch buten, related to Middle Low German bute "exchange" (see booty). Cf. filibuster. The back-formed verb freeboot is recorded from 1590s.
freedman (n.): "manumitted slave," c.1600, from past participle of free (adj.) + man (n.). Also cf. freeman.
freedom (n.): Old English freodom "freedom, state of free will; charter, emancipation, deliverance;" see free (adj.) + -dom. Freedom-rider recorded 1961, in reference to civil rights activists in U.S. trying to integrate bus lines.
It has been said by some physicians, that life is a forced state. The same may be said of freedom. It requires efforts, it presupposes mental and moral qualities of a high order to be generally diffused in the society where it exists. [John C. Calhoun, speech, U.S. House of Representatives, Jan. 31, 1816]

Freedom Rider Situation Cuts Into Montgomery Juke, Game Revenues [headline, "Billboard," July 24, 1961]
Freedom fighter attested by 1903 (originally with reference to Cuba).
freefall: also free fall, free-fall, 1919, originally of parachutists and in rocketry, from free (adj.) + fall (v.).
freehold (n.): early 15c. (implied in freeholder), translating Anglo-French fraunc tenement; see free (adj.) + hold (n.). Related: Freeholder.
freelance (n.): also free lance, free-lance, "medieval mercenary warrior," 1820 ("Ivanhoe"), from free (adj.) + lance (n.); apparently a coinage of Sir Walter Scott's. Figurative sense is from 1864; specifically of journalism by 1882.
freelance (v.): 1902, from freelance (n.). Related: Freelancer (1898); freelanced; freelancing.
freeloader (n.): also free-loader, by 1939, from free (adj.) + agent noun from load (v.). Related: Freeloading. As a verb, freeload is attested by 1967.
freely (adv.): Old English freolice; see free (adj.) + -ly (2).
freeman (n.): Old English freoman; see free (adj.) + man (n.).
Freemason (n.): late 14c., originally a traveling guild of masons with a secret code; in the early 17c. they began accepting honorary members and teaching them the secrets and lore, which by 1717 had developed into the fraternity of Free and Accepted Masons.

The exact origin of the free- is a subject of dispute. Some [e.g. Klein] see a corruption of French frère "brother," from frèremaçon "brother mason;" others say it was because the masons worked on "free-standing" stones; still others see them as "free" from the control of local guilds or lords [OED].
Freemasonry (n.): mid-15c., from freemason + -ry.
freer (n.): "one who sets free," c.1600, from free + -er (1).
freer (adj.): comparative of free. See -er (2).