'go to bed' definitions:

Definition of 'go to bed'

(from WordNet)
verb
Prepare for sleep; "I usually turn in at midnight"; "He goes to bed at the crack of dawn" [syn: go to bed, turn in, bed, crawl in, kip down, hit the hay, hit the sack, sack out, go to sleep, retire] [ant: arise, get up, rise, turn out, uprise]

Synonyms of 'go to bed'

From: Moby Thesaurus