1.
If you lock something up in a place or container, you put or hide it there and fasten the lock.
Give away any food you have on hand, or lock it up and give the key to the neighbours...
Control of materials could be maintained by locking up bombs.
PHRASAL VERB : V n P , V P n (not pron)
2.
To lock someone up means to put them in prison or a secure psychiatric hospital.
Mr Milner persuaded the federal prosecutors not to lock up his client...
PHRASAL VERB : V P n (not pron) , also V n P
3.
When you lock up a building or car or lock up , you make sure that all the doors and windows are locked so that nobody can get in.
Don’t forget to lock up...
Leave your car here and lock it up.
PHRASAL VERB : V P , V n P