stayyoudaoicibaDictYouDict[stay 词源字典]
stay: English has three distinct words stay, two of them ultimately from the same source. Stay ‘stop’ [15] comes from estai-, the present stem of Old French ester ‘stand, stop’. This in turn went back to Latin stāre ‘stand’ (source of English state, statue, etc). Staid [16] originated as the past participle of stay. Stay ‘strong rope’ [OE] comes from a prehistoric Germanic *staga-. This was derived from a base *stagh-, *stakh- ‘be firm’, which also produced English steel and (by borrowing) Old French estayer ‘support’ (source of English stay ‘support’ [16]).
=> staid, stand, statue; steel[stay etymology, stay origin, 英语词源]
stay (v.1)youdaoicibaDictYouDict
mid-15c., "cease going forward, come to a halt," also (transitive) "detain, hold back," from Old French estai-, stem of estare "to stay or stand," from Latin stare "to stand, stand still, remain standing; be upright, be erect; stand firm, stand in battle; abide; be unmovable; be motionless; remain, tarry, linger; take a side," (source also of Italian stare, Spanish estar "to stand, to be"), from PIE root *sta- "to stand" (see stet). Sense of "remain" is first recorded 1570s; that of "reside as a guest for a short period" is from 1550s. Related: Stayed; staying.

Of things, "remain in place," 1590s. Stay put is first recorded 1843, American English. "To stay put is to keep still, remain in order. A vulgar expression" [Bartlett]. Phrase stay the course is originally (1885) in reference to horses holding out till the end of a race. Stay-stomach was (1800) "a snack."
stay (n.1)youdaoicibaDictYouDict
"support, prop, brace," 1510s, from Middle French estaie "piece of wood used as a support," Old French estaie "prop, support," perhaps from Frankish *staka "support" or some other Germanic word, from Proto-Germanic *stagaz (cognates: Middle Dutch stake "stick," Old English steli "steel," stæg "rope used to support a mast"), from PIE *stak- "to stand, place" (see stay (n.2)). In some uses from stay (v.2).
stay (n.2)youdaoicibaDictYouDict
"strong rope which supports a ship's mast," from Old English stæg "rope used to support a mast," from Proto-Germanic *stagaz (cognates: Dutch stag, Low German stach, German Stag, Old Norse stag "stay of a ship"), from PIE *stak- "to stand, place," perhaps ultimately an extended form of root *sta- "to stand" (see stet).
stay (n.3)youdaoicibaDictYouDict
1520s, "delay, postponement, period of remaining in a place," from stay (v.1). Meaning "action of stoppage, appliance for stopping" is 1530s; that of "suspension of judicial proceedings" is from 1540s.
stay (v.2)youdaoicibaDictYouDict
"support, sustain," early 15c., from Middle French estayer (Modern French étayer), originally in nautical use, "secure by stays," from estaie (see stay (n.1)). The nautical sense in English is from 1620s. Related: Stayed; staying.