Stay
late Middle English (as a verb): from Anglo-Norman French estai-, stem of Old French ester, from Latin stare ‘to stand’; in the sense ‘support’ (stay1 (sense 5 of the verb) and stay1 (sense 3 of the noun)), partly from Old French estaye (noun), estayer (verb), of Germanic origin.
wiktionary
From Middle English steyen, staien, from Old French estayer, estaier(“to fix, prop up, support, stay”), from estaye, estaie(“a prop, stay”), from Middle Dutch staeye(“a prop, stay”), a contracted form of staede, stade(“a prop, stay, help, aid”) (compare Middle Dutch staeyen, staeden(“to make firm, stay, support, hold still, stabilise”)), from Frankish *stad(“a site, place, location, standing”), from Proto-Germanic *stadiz(“a standing, place”), from Proto-Indo-European *stéh₂tis(“standing”). Influenced by Old English stæġ("a stay, rope"; see below). Cognate with Old English stede, stæde(“a place, spot, locality, fixed position, station, site, standing, status, position of a moving body, stopping, standing still, stability, fixity, firmness, steadfastness”), Swedish stödja(“to prop, support, brace, hold up, bolster”), Icelandic stöðug(“continuous, stable”). More at stead, steady.
Sense of "remain, continue" may be due to later influence from Old French ester, esteir(“to stand, be, continue, remain”), from Latin stāre(“stand”), from the same Proto-Indo-European root above; however, derivation from this root is untenable based on linguistic and historical grounds [1].
An alternative etymology derives Old French estaye, estaie, from Frankish *staka(“stake, post”), from Proto-Germanic *stakô(“stake, bar, stick, pole”), from Proto-Indo-European *(s)teg-(“rod, pole, stick”), making it cognate with Old English staca(“pin, stake”), Old English stician(“to stick, be placed, lie, remain fixed”). Cognate with Albanian shtagë(“a long stick, a pole”). More at stake, stick.
From Middle English stay, from Old French estaye, estaie(“a prop, a stay”), from Middle Dutch staeye(“a prop, stay”), a contracted form of staede, stade("a prop, stay, help, aid"; compare Middle Dutch staeyen, staeden(“to make firm, stay, support, hold still, stabilise”)), from Old Dutch *stad(“a site, place, location, standing”), from Proto-Germanic *stadiz(“a standing, place”), from Proto-Indo-European *steh₂-(“to stand”). See above.
From Middle English stay, from Old English stæġ(“stay, a rope supporting a mast”), from Proto-Germanic *stagą(“stay, rope”), from Proto-Indo-European *stek-, *stāk-(“stand, pole”), from Proto-Indo-European *steh₂-(“to stand”). Cognate with Dutch stag(“stay”), German Stag(“stay”), Swedish stag(“stay”), Icelandic stag(“stay”).
From Middle English *steȝe, from Old English *stǣġe, an apocopated variant of stǣġel(“steep, abrupt”), from Proto-Germanic *staigilaz(“climbing, ascending, sloping, steep”), see sty.
etymonline
stay (v.1)
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, make or be firm." 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)
"support, prop, brace," 1510s, from 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 (source also of 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)
"strong rope which supports a ship's mast," from Old English stæg "rope used to support a mast," from Proto-Germanic *stagaz (source also of 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, make or be firm."
stay (v.2)
"support, sustain," early 15c., from 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.
stay (n.3)
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.
