A person who or thing which imposes punishment on an offender or for an offence. Frequently with of.

One who chastises.

figurative. One who punishes or oppresses; one who ‘lashes’ with satire or invective.

One who visits with punishment. rare.

gen. One who carries a sentence or judgement into effect: a punisher.

= visitor, n. 2a 2b.

transferred.

An inflicter of punishment, a chastiser. Obsolete. rare.