flooryoudaoicibaDictYouDict[floor 词源字典]
floor: [OE] Floor and its first cousins, German flur ‘paved floor’ and Dutch vloer ‘floor’, go back to a prehistoric Germanic *flōruz. They are related to various Celtic words for ‘floor’, including Old Irish lār, Welsh llawr, and Breton leur, and it has been speculated that both the Germanic and the Celtic words come ultimately from the same source as Latin plānus ‘flat’ and English flat, and denote etymologically ‘flat surface’.
=> flat[floor etymology, floor origin, 英语词源]
floor (v.)youdaoicibaDictYouDict
early 15c., "to furnish with a floor," from floor (n.). Sense of "puzzle, confound" is from 1830, a figurative use, from earlier sense of "knock down to the floor" (1640s). In mid-19c. English university slang, it meant "do thoroughly and successfully" (1852). Related: Floored; flooring.
floor (n.)youdaoicibaDictYouDict
Old English flor "floor, pavement, ground, bottom (of a lake, etc.)," from Proto-Germanic *floruz "floor" (cognates: Middle Dutch and Dutch vloer, Old Norse flor "floor," Middle High German vluor "floor, flooring," German Flur "field, meadow"), from PIE *plaros "flat surface" (source also of Welsh llawr "ground"), enlarged from *pele- (2) "flat, broad; to spread out" (see plane (n.1)).

Meaning "level of a house" is from 1580s. The figurative sense in legislative assemblies (1774) is in reference to the "floor" where members sit and from which they speak (as opposed to the platform). Spanish suelo "floor" is from Latin solum "bottom, ground, soil;" German Boden is cognate with English bottom (n.). Floor-plan is attested from 1794; floor-board from 1787, floor-lamp from 1886, floor-length (adj.) of dresses is from 1910. The retail store's floor-walker is attested from 1862.