firm (adj.)youdaoicibaDictYouDict[firm 词源字典]
late 14c., ferm, "strong, steady" (of things), "permanent, enduring" (of agreements), "steadfast, steady" (of persons), "sound, well-founded" (of arguments), from Old French ferm "strong, vigorous; healthy, sound; steadfast, loyal, faithful" (12c.), from Latin firmus "strong, steadfast, enduring, stable," figuratively "constant, steadfast, trusty, faithful," from PIE root *dher- (2) "to hold, support" (cognates: Sanskrit dharmah "custom, law," Greek thronos "seat," Lithuanian dirzmas "strong," Welsh dir "hard," Breton dir "steel"). The spelling return to -i- in late 1500s was modeled on Latin. Related: Firmly; firmness.[firm etymology, firm origin, 英语词源]
firm (n.)youdaoicibaDictYouDict
"business house," 1744, according to Barnhart from German Firma "a business, name of a business," originally "signature," from Italian firma "signature," from firmare "to sign," from Latin firmare "make firm, affirm," in Late Latin, "confirm (by signature)," from firmus "firm, stable" (see firm (adj.)).
firm (v.)youdaoicibaDictYouDict
c. 1300, fermen "make firm, establish," from Old French fermer "consolidate; fasten, secure; build, set up; fortify" (12c.) or directly from Latin firmare "make firm; affirm; strengthen, fortify, sustain; establish, prove, declare," from firmus "strong, steadfast, stable" (see firm (adj.)). Intransitive use, "become firm" is from 1879; with up (adv.) from 1956. Related: Firmed; firming.
firmament (n.)youdaoicibaDictYouDict
mid-13c., from Old French firmament or directly from Latin firmamentum "firmament," literally "a support, a strengthening," from firmus "strong, steadfast, enduring" (see firm (adj.)). Used in Late Latin in the Vulgate to translate Greek stereoma "firm or solid structure," which translated Hebrew raqia, a word used of both the vault of the sky and the floor of the earth in the Old Testament, probably literally "expanse," from raqa "to spread out," but in Syriac meaning "to make firm or solid," hence the erroneous translation. Related: Firmamental.
firmware (n.)youdaoicibaDictYouDict
1968, from firm (adj.) + ending from software.
firn (n.)youdaoicibaDictYouDict
"consolidated snow, the raw material of glaciers," 1839, literally "last year's snow, névé," from German Firn, from Swiss dialectal firn "of last year," from Middle High German virne "old," from Old High German firni, related to Old English fyrn "old," Gothic fairns "of last year," from Proto-Germanic *fur- "before" (see fore (adv.)).

The only living English relic of a useful word meaning "of last year" that was widespread in Indo-European languages (cognates: Lithuanian pernai "last year" (adv.), Greek perysi "a year ago, last year," Sanskrit parut "of last year;" also German Firnewein "wine of last year"). Old English had fyrngemynd "ancient history," more literally, "memory of long ago;" fyrnmann "man of old times;" fyrnnes "antiquity;" fyrnsægen "old saying." Middle English retained fern "long ago, formerly, of old," fern-days "days of old, former year, a year past."
first (adj., adv.)youdaoicibaDictYouDict
Old English fyrst "foremost, going before all others; chief, principal," also (though rarely) as an adverb, "at first, originally," superlative of fore; from Proto-Germanic *furista- "foremost" (cognates: Old Saxon fuirst "first," Old High German furist, Old Norse fyrstr, Danish første, Old Frisian ferist, Middle Dutch vorste "prince," Dutch vorst "first," German Fürst "prince"), from PIE *pre-isto-, superlative of *pre-, from root *per- (1) "forward, through" (see per).

The usual Old English superlative word was not fyrst, but forma, which shows more clearly the connection to fore. Forma became Middle English firme "first, earliest," but this has not survived.

First aid is that given at the scene, pending the arrival of a doctor. First Lady as an informal title for the wife of a U.S. president was in use by 1908, short for First lady of the land (by 1863 with reference to the president's wife). First name is attested from mid-13c. First base "a start" in any sense (1938) is a figurative use from baseball.

First-fruits is from late 14c. as "earliest productions of the soil;" 1590s as "first results" of any activity or endeavor. First love is from 1741 as "one's first experience of romantic love;" 1971 as "one's favorite occupation or pastime." First-floor is from 1660s as "story built on or just above the ground" (now U.S.); 1865 as "story built next above the ground."
first (n.)youdaoicibaDictYouDict
1560s, "that which is first," from first (adj.). Meaning "first day of the month" is by 1590s. In music, "instrument or voice that takes the highest or chief part of its class," 1774. From 1909 as the name of the lowest gear in an engine. In British schools colloquial use, "highest rank in an examination," 1850.
first-born (adj., n.)youdaoicibaDictYouDict
mid-14c., from first (adj.) + born.
first-class (adj.)youdaoicibaDictYouDict
"of the highest class" with reference to some standard of excellence, 1837, from first (adj.) + class (n.). Specifically in reference to conveyances for travel, 1846. In reference to U.S. Mail, 1875.
first-hand (adj.)youdaoicibaDictYouDict
also firsthand, "direct from the source or origin," 1690s, from the image of the "first hand" as the producer or maker of something.
first-rate (adj.)youdaoicibaDictYouDict
"of the highest excellence," 1660s, from first (adj.) + rate (n.) in a specific sense "class of warships in the British Navy." As a mere emphatic statement expressing excellence, by 1812. Colloquially, as a quasi-adverb, 1844.
first-timer (n.)youdaoicibaDictYouDict
"rookie, one doing something for the first time," 1888, from first time; see first (adj.) + time (n.).
firstly (adv.)youdaoicibaDictYouDict
"in the first place, before anything else," 1530s, but never a common word (simple first usually serving its place), from first + -ly (2).
firth (n.)youdaoicibaDictYouDict
"arm of the sea, estuary of a river," early 15c., Scottish, from Old Norse fjörðr (see fjord).
fiscal (adj.)youdaoicibaDictYouDict
1560s, "pertaining to public revenue," from Middle French fiscal, from Late Latin fiscalis "of or belonging to the state treasury," from Latin fiscus "state treasury," originally "money bag, purse, basket made of twigs (in which money was kept)," which is of unknown origin. The etymological notion is of the public purse. The general sense of "financial" (1865, American English) was abstracted from phrases fiscal calendar, fiscal year, etc. Related: Fiscally.
fish (n.)youdaoicibaDictYouDict
Old English fisc "fish," from Proto-Germanic *fiskaz (cognates: Old Saxon, Old Frisian, Old High German fisc, Old Norse fiskr, Middle Dutch visc, Dutch vis, German Fisch, Gothic fisks), from PIE *peisk- "fish" (cognates: Latin piscis, Irish iasc, and, via Latin, Italian pesce, French poisson, Spanish pez, Welsh pysgodyn, Breton pesk).

Popularly, since Old English, "any animal that lives entirely in the water," hence shellfish, starfish (an early 15c. manuscript has fishes bestiales for "water animals other than fishes"). The plural is fishes, but in a collective sense, or in reference to fish meat as food, the singular fish generally serves for a plural. In reference to the constellation Pisces from late 14c. Fish (n.) for "person" is from 1750 in the faintly dismissive sense; earlier it was used in reference to a person considered desirable to 'catch' (1722). Figurative sense of fish out of water first recorded 1610s. To drink like a fish is from 1744. To have other fish to fry "other objects which invite or require attention" is from 1650s.

Fish-story attested from 1819, from the tendency to exaggerate the size of the catch (or the one that got away). Fish-eye as a type of lens is from 1961. Fish-and-chips is from 1876; fish-fingers from 1962. Fish-food is from 1936 as "food for (pet or hobby) fish."
fish (v.)youdaoicibaDictYouDict
Old English fiscian "to fish, to catch or try to catch fish" (cognates: Old Norse fiska, Old High German fiscon, German fischen, Gothic fiskon), from the root of fish (n.). Related: Fished; fishing.
fish-hookyoudaoicibaDictYouDict
late 14c., from fish (n.) + hook (n.).
fish-tail (n.)youdaoicibaDictYouDict
1840, "the tail of a fish," from fish (n.) + tail (n.). As a verb, also fishtail, 1927, originally of aircraft, later automobiles. Related: Fishtailed; fishtailing.