floatyoudaoicibaDictYouDict[float 词源字典]
float: [OE] Germanic *fleut-, which produced English fleet, had the so-called ‘weak grades’ (that is, variant forms which because they were weakly stressed had different vowels) *flot- and *flut-. The former was the source of Germanic *flotōjan, which passed into late Old English as flotian and eventually ousted flēotan (modern English fleet) from its original meaning ‘float’.

It also seems to have been borrowed into the Romance languages, producing French flotter, Italian fiottare, and Spanish flotar (a diminutive of the Spanish noun derivative flota gave English flotilla [18]). The latter formed the basis of Old Norse flytja, acquired by English as flit [12], and of Old English floterian, which became modern English flutter.
=> fleet, flit, flotilla, flutter[float etymology, float origin, 英语词源]
float (v.)youdaoicibaDictYouDict
late Old English flotian "to rest on the surface of water" (intransitive; class II strong verb; past tense fleat, past participle floten), from Proto-Germanic *flotan "to float" (cognates: Old Norse flota, Middle Dutch vloten, Old High German flozzan, German flössen), from *flot-, from PIE *pleud-, extended form of root *pleu- "to flow" (see pluvial).

Meaning "drift about, hover passively" is from c. 1300. Transitive sense of "to lift up, cause to float" (of water, etc.) is from c. 1600; that of "set (something) afloat" is from 1778 (originally of financial operations). Of motion through air, from 1630s. Meaning "hover dimly before the eyes" is from 1775. Related: Floated; floating. A floating rib (by 1802) is so called because the anterior ends are not connected to the rest.
float (n.)youdaoicibaDictYouDict
apparently an early Middle English merger of three related Old English nouns, flota "boat, fleet," flote "troop, flock," flot "body of water, sea;" all from the source of float (v.). The early senses were the now-mostly-obsolete ones of the Old English words: "state of floating" (early 12c.), "swimming" (mid-13c.); "a fleet of ships; a company or troop" (c. 1300); "a stream, river" (early 14c.). From c. 1300 as an attachment for buoyancy on a fishing line or net; early 14c. as "raft." Meaning "platform on wheels used for displays in parades, etc." is from 1888, probably from earlier sense of "flat-bottomed boat" (1550s). As a type of fountain drink, by 1915.
Float.--An ade upon the top of which is floated a layer of grape juice, ginger ale, or in some cases a disher of fruit sherbet or ice cream. In the latter case it would be known as a "sherbet float" or an "ice-cream float." ["The Dispenser's Formulary: Or, Soda Water Guide," New York, 1915]


Few soda water dispensers know what is meant by a "Float Ice Cream Soda." This is not strange since the term is a coined one. By a "float ice cream soda" is meant a soda with the ice cream floating on top, thus making a most inviting appearance and impressing the customer that you are liberal with your ice cream, when you are not really giving any more than the fellow that mixes his ice cream "out of sight." ["The Spatula," Boston, July, 1908]