What is the suffix of the word resentment?

The suffix of the word resentment would be '-ment'.

Explanation:

The suffix '-ment' means to do something or the result of an action. Resent means to feel bitterness towards someone or something, so together, resentment would mean the act of resenting or being resented by someone.

noun a feeling of deep and bitter anger and ill-will. gall; rancour; rancor; bitterness.