Stead means the place of somebody else. In his stead, stand in her stead, serve in good stead.
It survives in two phrases and nowhere else. In somebody's stead means in their place, and is formal and rare. Stand somebody in good stead means to be useful to them later — that training will stand you in good stead — which is much the commoner of the two. Note that stead is the Old English word for a place, which survives in homestead, bedstead and hundreds of place names.
1nounsteadThe place of somebody else.
“The captain was injured, so his deputy led the team in his stead.”
stead is a place or position.
Old English stede meant a place, from a root about standing. Instead, homestead, bedstead and the German Stadt come from the same place.
Proto-Indo-European
*steh₂-
Proto-Indo-European
*stéh₂tis — standing, location
Proto-Germanic
*stadiz — place
Old English
stede
Middle English
sted
English, today
stead
From Middle English sted and steden, from Old English stede, from Proto-Germanic stadiz (“place”), from Proto-Indo-European stéh₂tis (“standing, location”). a doublet of stad. 2 Cognate with Scots steid (“location, place”), frr Stair, Stat, steed, stää (“city, town; place, stead”), stq Steede (“place, stead”), Stääd (“city, town”), West Frisian stêd (“city, town”), bar Stådt (“city, town”), Dutch stad, stede (“city, town”), German Stadt (“city, town”), Statt (“abode, place, stead”), Stätte (“place, spot, venue”), German Low German Stee (“location, place”), lb Stad (“city, town”), wym śtaod (“city, town”), Yiddish שטאָט (“city, town”), Danish -, Norwegian Bokmål stad (“city, town”), sted (“place”), Faroese stað (“place”), staður (“location, place; town”), Icelandic staður (“location, place”), nrn sta (“domicile, farm”), Norwegian Nynorsk stad (“place; city, town”), Swedish stad, stadh, stedt (“city, town”), Gothic 𐍃𐍄𐌰𐌸𐍃 (“location, place”). See the doublet a doublet of stasis.
Etymology from Wiktionary, CC BY-SA