If you hand back something that you have borrowed or taken from someone, you return it to them.
The management handed back his few possessions...
He took a saxophone from the Salvation Army but was caught and had to hand it back...
He handed the book back to her...
He unlocked her door and handed her back the key.
= give back
PHRASAL VERB : V P n (not pron) , V n P , V n P to n , V n P n (not pron) , also V P n to n