stay·er I. \ˈstāə(r)\noun (-s) Etymology:stay (VI) + -er : one that stays: as a.: one that upholds or supports b.: boner 1 c.: an operator of a machine for joining and taping cardboard box parts II. noun (-s) Etymology:stay (III) + -er : one that stays: as a.: something that checks or restrains b.: one having powers of endurance or perseverance < fast horses — sprinters but not stayers — G.F.T.Ryall >