fixed (adj.)youdaoicibaDictYouDict[fixed 词源字典]
late 14c., of stars, "unchangeable in position," past participle adjective from fix (v.). Related: fixedly (1590s). Fixed-income (n.) is from 1767.[fixed etymology, fixed origin, 英语词源]
fixer (n.)youdaoicibaDictYouDict
1849, of chemicals, etc.; 1885 as a person who "makes things right;" agent noun from fix (v.). Fixer-upper is from 1967 as "that which repairs other things" (in an advertisement for a glue); by 1976 as a real-estate euphemism for "property that needs a lot of work."
fixings (n.)youdaoicibaDictYouDict
"apparatus," 1820, American English, from fixing "act of putting in order" (c. 1600), verbal noun from fix (v.). American English sense of "food, garnishing" is attested from 1839.
fixity (n.)youdaoicibaDictYouDict
1660s in physics; general use from 1791; see fix (v.) + -ity.
fixture (n.)youdaoicibaDictYouDict
1590s, "act of fixing," perhaps from fix (v.) on model of mixture, or from an assumed Latin *fixitatem. Meaning "anything fixed or securely fastened" is from 1812, an alteration of fixure (c. 1600).
fizgig (n.)youdaoicibaDictYouDict
"light, frivolous woman," 1520s, first element of uncertain origin, second element is Middle English gig "frivolous person" (see gig (n.1)).
fizz (v.)youdaoicibaDictYouDict
"make a hissing sound," 1660s, of imitative origin. Related: Fizzed; fizzing. The noun is recorded from 1812; meaning "effervescent drink" is from 1864, from the sound it makes.
fizzle (v.)youdaoicibaDictYouDict
1530s, "to break wind without noise," probably altered from obsolete fist, from Middle English fisten "break wind" (see feisty) + frequentative suffix -le. Related: Fizzled; fizzling.

Meaning "make a noise as of a liquid or gas forced out a narrow aperture" is from 1859, "usually with special reference to the weakness and sudden diminution or cessation of such sound" [Century Dictionary], hence the figurative sense "prove a failure, stop abruptly after a more-or-less brilliant start." But this sense is earlier and dates to at least 1847 in American English college slang, along with the noun sense of "failure, fiasco" (1846), also originally U.S. college slang, "a failure in answering an examination by a professor." Barnhart says it is "not considered as derived from the verb." Halliwell ("Archaic and Provincial Words," 1846) has fizzle (v.) as "To do anything without noise," which might connect the college slang with the older word via some notion of mumbled and stifled performance:
In many colleges in the United States, this word is applied to a bad recitation, probably from the want of distinct articulation, which usually attends such performances. It is further explained in the Yale Banger, November 10, 1846: "This figure of a wounded snake is intended to represent what in technical language is termed a fizzle. The best judges have decided that to get just one third of the meaning right constitutes a perfect fizzle." [John Bartlett, "A Collection of College Words and Customs," Cambridge, 1851]
fizzy (adj.)youdaoicibaDictYouDict
1885, from fizz + -y (2).
fjord (n.)youdaoicibaDictYouDict
1670s, from Norwegian fiord, from Old Norse fjörðr, from North Germanic *ferthuz, from PIE *prtus, from *per- "going, passage" (see port (n.1)).
flab (n.)youdaoicibaDictYouDict
"fat, flabbiness," 1951, back-formation from flabby.
flabbergast (v.)youdaoicibaDictYouDict
1772, flabbergasted, mentioned (with bored) in a magazine article that year as a new vogue word, of uncertain origin. Perhaps from some dialect (in 1823 flabbergast was noted as a Sussex word), perhaps ultimately an arbitrary formation alluding to flabby or flapper and aghast. "Like many other popular words expressing intensity of action, ... not separable into definite elements or traceable to a definite origin" [Century Dictionary]. Related: Flabbergasted; flabbergasting; flabbergastation.
flabbergasted (adj.)youdaoicibaDictYouDict
see flabbergast.
flabby (adj.)youdaoicibaDictYouDict
1690s, regarded as a softened variant of flappy, which is recorded in the sense of "softly fleshy" from 1590s; see flap (n.). Related: Flabbily; flabbiness.
flaccid (adj.)youdaoicibaDictYouDict
1610s, from French flaccide or directly from Latin flaccidus "flabby, pendulous, weak, drooping," from flaccus "flabby, flap-eared," which is of uncertain origin (OED suggests it's imitative). Related: Flaccidly; flacidness; flaccidity; flaccescency.
flack (n.)youdaoicibaDictYouDict
"publicity or press agent," 1945, also by that year as a verb, said to have been coined at show biz magazine "Variety" (but the first attested use is not in "Variety") and supposedly from name of Gene Flack, a movie agent, but influenced by flak. There was a Gene Flack who was an advertising executive in the U.S. during the 1940s, but he seems to have sold principally biscuits, not movies.
flag (n.1)youdaoicibaDictYouDict
"cloth ensign," late 15c., now in all modern Germanic languages (German Flagge, Dutch vlag, Danish flag, Swedish flagg, etc.) but apparently first recorded in English, of unknown origin, but likely connected to flag (v.1) or else an independent imitative formation "expressing the notion of something flapping in the wind" [OED]. A guess considered less likely is that it is from flag (n.2) on the notion of being square and flat.

Meaning "name and editorial information on a newspaper" is by 1956. U.S. Flag Day (1894) is in reference to the adopting of the Stars and Stripes by the Continental Congress on June 14, 1777.
flag (v.1)youdaoicibaDictYouDict
1540s, "flap about loosely," probably a later variant of Middle English flakken, flacken "to flap, flutter" (late 14c.), which probably is from Old Norse flaka "to flicker, flutter, hang losse," perhaps imitative of something flapping lazily in the wind. Sense of "go limp, droop, become languid" is first recorded 1610s. Related: Flagged; flagging.
flag (n.2)youdaoicibaDictYouDict
"flat stone for paving," c. 1600, ultimately from Old Norse flaga "stone slab," from Proto-Germanic *flago- (see flake (n.)). Earlier in English as "piece cut from turf or sod" (mid-15c.), from Old Norse flag "spot where a piece of turf has been cut out," from flaga.
flag (n.3)youdaoicibaDictYouDict
plant growing in moist places, late 14c., "reed, rush," perhaps from Scandinavian (compare Danish flæg "yellow iris") or from Dutch flag; perhaps ultimately connected to flag (v.1) on notion of "fluttering in the breeze."