From Longman Dictionary of Contemporary Englishsleep something ↔ off phrasal verb informalSLEEPto sleep until you do not feel ill anymore, especially after drinking too much alcohol He went to his room to sleep it off. → sleep→ See Verb table
Examples from the Corpus
sleep off• Go someplace and sleep it off.• I know him, he's a mate, probably just had a few and he's sleeping it off.• Night Cream a rich blend to restore moisture balance while you sleep.• Placed on report, Wait was told to go below and sleep it off.• So you needed to sleep it off.• Steven Perez thought his mommy was just sleeping.• You threw a blanket over your wife and let her sleep it off.• The square was empty, except for a pair of winos sleeping it off under the statue.sleep it off• Go someplace and sleep it off.• I know him, he's a mate, probably just had a few and he's sleeping it off.• Placed on report, Wait was told to go below and sleep it off.• So you needed to sleep it off.• You threw a blanket over your wife and let her sleep it off.• If some local traveller wanted to sleep it off in the Rectory, who was she to say he should not.• The square was empty, except for a pair of winos sleeping it off under the statue. 