Sleepers meaning : Someone who sleeps. That which lies dormant, as a law. A spy, saboteur, or terrorist who lives unobtrusively in a community until activated by a prearranged signal; may be part of a sleeper cell. A small starter earring, worn to prevent a piercing from closing. A railway sleeping car. A sleeper hold. Something that achieves unexpected success after an interval of time. A goby-like bottom-feeding freshwater fish of the family Odontobutidae. A nurse shark (family Ginglymostomatidae). A type of pajama for a person, especially a child, that covers the whole body, including the feet. An automobile which has been internally modified to excess, while retaining a mostly stock appearance in order to fool opponents in a drag race, or to avoid the attention of the police. A sedative. A railroad tie. A structural beam in a floor running perpendicular to both the joists beneath and floorboards above. A heavy floor timber in a ship's bottom. The lowest, or bottom, tier of casks.