neatyoudaoicibaDictYouDict[neat 词源字典]
neat: English has two words neat. The older is now virtually obsolete, while the commoner is a comparatively recent introduction. Neat ‘tidy’ [16] was borrowed from French net ‘neat, clean’. This goes back to Latin nitidus ‘elegant, shiny’, a derivative of the verb nītēre ‘shine’. English originally acquired the word in the 14th century as net ‘clean, tidy’ (from which the modern net ‘with deductions’ developed).

This had a 16thcentury derivative netty, which may be the source of modern English natty [18]. Neat ‘cow, ox’ [OE] is now encountered only in gastronomic contexts, such as ‘neat’s foot jelly’, and even then is an archaism. It goes back to prehistoric Germanic *nautam, a derivative of a base meaning ‘use’, and hence reflects (like cattle itself) the original notion of cattle as ‘useful property’.
=> natty, net[neat etymology, neat origin, 英语词源]
neat (adj.)youdaoicibaDictYouDict
1540s, "clean, free from dirt," from Anglo-French neit, Middle French net "clear, pure" (12c.), from Latin nitidus "well-favored, elegant, trim," literally "gleaming," from nitere "to shine," from PIE root *nei- "to shine" (cognates: Middle Irish niam "gleam, splendor," niamda "shining;" Old Irish noib "holy," niab "strength;" Welsh nwyfiant "gleam, splendor").

Meaning "inclined to be tidy" is from 1570s. Of liquor, "straight," c. 1800, from meaning "unadulterated" (of wine), which is first attested 1570s. Informal sense of "very good" first recorded 1934 in American English; variant neato is teenager slang, first recorded 1968. Related: Neatly; neatness.
neat (n.)youdaoicibaDictYouDict
"ox, bullock, cow," Old English neat "ox, beast, animal," from Proto-Germanic *nautam "thing of value, possession" (cognates: Old Frisian nat, Middle Dutch noot, Old High German noz, Old Norse naut), from PIE root *neud- "to make use of, enjoy."