withhold (v)
keep back (v)

Definition: hold back
Example: The father is withholding the allowance until the son cleans his room.

restrain (v)
keep back (v)
keep (v)
hold back (v)

Definition: prevent the action or expression of
Example: hold back your anger. keep your cool. she struggled to restrain her impatience at the delays.

retain (v)
keep back (v)
hold back (v)
hold (v)

Definition: secure and keep for possible future use or application
Example: The landlord retained the security deposit. I reserve the right to disagree.