apologia C2+

/ˌæpəˈloʊdʒiə/ a formal written defence of one's opinions or conduct

apologist C2+

/əˈpɑlədʒɪst/ a person who argues in defense of a controversial doctrine or institution

apologizer C2+

/əˈpɑləˌdʒaɪzɚ/ a person who apologizes or expresses regret