<p><strong>Noun</strong></p><ul><li>A person or thing that sleeps.</li><li>A heavy horizontal timber for distributing loads.</li><li>Any long wooden, metal, or stone piece lying horizontally as a sill or footing.</li><li>Any of a number of wooden pieces, laid upon the ground or upon masonry or concrete, to which floorboards are nailed.</li><li>A sleeping car.</li><li>Informal: something or someone that becomes unexpectedly successful or important after a period of being unnoticed, ignored, or considered unpromising or a failure (e.g., "The play was the sleeper of the season").</li><li>Merchandise that is not quickly sold because its value is not immediately recognized.</li><li>Often plural: one-piece or two-piece pajamas with feet, especially for children.</li><li>A sofa, chair, or other piece of furniture that is designed to open up or unfold into a bed; convertible.</li><li>A globule that forms at the inner corner of the eye, especially during sleep, from the accumulated secretion of the glands of the eyelid.</li><li>Any of several gobioid fishes of the family Eleotridae, of tropical seas, most species of which have the habit of resting quietly on the bottom.</li><li>Slang: a spy; mole.</li><li>Slang: a juvenile delinquent sentenced to serve more than nine months.</li><li>Bowling: a pin that is hidden from view by another pin.</li><li>Chiefly British: a timber or beam laid in a railroad track, serving as a foundation or support for the rails; tie.</li></ul>