1.
If you lock something away in a place or container, you put or hide it there and fasten the lock.
She meticulously cleaned the gun and locked it away in its case...
He had even locked away all the videos of his previous exploits.
PHRASAL VERB: V n P, V P n (not pron)
2.
To lock someone away means to put them in prison or a secure mental hospital.
Locking them away is not sufficient, you have to give them treatment.
PHRASAL VERB: V n P, also V P n (not pron)
3.
If you lock yourself away, you go somewhere where you can be alone, and do not come out or see anyone for some time.
I locked myself away with books and magazines.
= hide away, shut away
PHRASAL VERB: V pron-refl P