noun

1. a person or animal that sleeps, esp. as specified a sound sleeper
2. a timber or beam laid horizontally, as on the ground, to support something above it
3. Chiefly Brit. a tie supporting a railroad track
4. ☆ sleeping car
5. ☆ a previously disregarded person or thing that unexpectedly achieves success, assumes importance, etc.
6. Slang mole (sense )
7. ☆
   1. a kind of pajamas for infants and young children, that enclose the feet
   2. bunting (sense )
8. ☆ Bowling a pin concealed by one in front of it, in bowling for a spare

Etymology: ME slepere < OE slæpere