Stories We Like: A Guide to the Comma
c.1300, "freed from dregs or lees" (of ale, wine, etc.), i.e. "having stood long enough to clear," cognate with Middle Dutch stel "stale" (of beer), and probably ultimately from Proto-Germanic base *sta- "stand," the source of Old English standan "to stand," Perhaps via Old French estaler "halt," from Frankish *stal- "position" (see stall (n.1)). The meaning "not fresh" is first recorded late 15c. Figurative sense (of immaterial things) is recorded from 1560s. Related: Staleness.