sleeper

From Wiktionary

Word parts[change]

sleep + -er

Pronunciation[change]

Noun[change]

Singular
sleeper

Plural
sleepers

  1. (countable) A sleeper is a person who sleeps.
  2. (countable) A sleeper is a train that carries sleeping cars.
  3. (countable) A sleeper is someone or something that looks ordinary but has a secret function that will be used at a much later time.