Meaning

• Someone who sleeps.

  "I'm a light sleeper: I get woken up by the smallest of sounds."

• 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.

  "We spent a night on an uncomfortable sleeper between Athens and Vienna."

• A sleeper hold.

• Something that achieves unexpected success after an interval of time.

  "A box-office bomb when it first came out, the film was a sleeper, becoming much more popular decades after being released."

• 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.

  "Aaron, Devin, and Laura looked so comfy in their sleepers."

• 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.

Meaning

• To mark a calf by cutting its ear.