noun
plural -ers
[count] a person who sleeps in a particular way
someone who is asleep
a place or piece of furniture that can be used for sleeping - usually used before another noun
sleeping car
chiefly US informal :someone or something that suddenly becomes successful in a way that was not expected
a spy who lives and works for a long time like an ordinary person among the people he or she is spying on - often used before another noun
US :a piece of clothing that covers the entire body including usually the feet and that is worn by a baby or small child
Brit :one of the heavy beams to which the rails of a railway are attached :tie