[sleep.er] n (12c) 1: one that sleeps
2: a piece of timber, stone, or steel on or near the ground to support a superstructure, keep railroad rails in place, or receive floor joists: stringpiece
3: sleeping car
4: someone or something unpromising or unnoticed that suddenly attains prominence or value "the low-budget film became the summer's ~"
5: children's pajamas usu. with feet--usu. used in pl.
6. chiefly Brit: a small earring or stud worn to keep the hole of a pierced ear from closing 7: mole
4.