how come "turn in" means go to sleep?
I looked up OED,it says that "turn in" could mean "go to sleep",I just want to know how does that come?
Solution 1:
Usage of “turn in” as an idiomatic expression meaning “go to bed” dates back to the 17th century and its origin appears to be from nautical jargon:
Turn in:
- to go to bed.
1695 [UK] Congreve Love for Love III i: I mean to toss a can, and remember my sweetheart afore I turn in.
1751 [UK] Smollett Peregrine Pickle (1964) 584: You sister Mrs. Clover keeps close watch upon her kinsman, without ever turning in.
1767 [US] ‘Andrew Barton’ Disappointment II i: Let’s step into the state-room and turn in.
(Green’s Dictionary of Slang)
Unluckily GDoS doesn’t explain how turn in come to mean “go to bed”, but one suggestion comes from The Phrase Finder
I believe the space on old-times boats was quite limited and the sailors' beds (most probably of hamac-type in two tiers) had a very restrictive clearance to accommodate a person (which is the case even nowadays on small boats). Therefore the person to go to bed had to literally "turn in".
and also Etymonline suggests a possible nautical origin
Turn in:
American English. Turn in "go to bed" is attested from 1690s, originally nautical.
and according to A Dictionary of Slang and Unconventional English turn in:
1695 (Congreve) colloquial nautical till mid 19th century, then a general usage.