'lock up' definitions:

Definition of 'lock up'

From: WordNet
verb
Secure by locking; "lock up the house before you go on vacation"
verb
Place in a place where something cannot be removed or someone cannot escape; "The parents locked her daughter up for the weekend"; "She locked her jewels in the safe" [syn: lock in, lock away, lock, put away, shut up, shut away, lock up]

Synonyms of 'lock up'

From: Moby Thesaurus