"Night, folks; I'm off to kip."
noun
1British a sleep or nap:
I might have a little kip
[mass noun] :
he was trying to get some kipverb (kips, kipping, kipped)
[no object] British
sleep:
he can kip on her sofa
Oxford Dictionaries has it as:
mid 18th century (in the sense 'brothel'): perhaps related to Danish kippe 'hovel, tavern'
Any further etymological info?