c.1300, "freed from dregs or lees" (of ale, wine, etc.), i.e. "having stood long enough to clear," cognate with M.Du. stel
"stale" (of beer), and probably ult. from P.Gmc. base *sta-
"stand," the source of O.E. standan
"to stand," Perhaps via O.Fr. estaler
"halt," from Frankish *stal-
"position" (see stall
(1)). The meaning "not fresh" is first recorded late 15c. Figurative sense (of immaterial things) is recorded from 1560s.