perfectionism Syllabification: (per·fec·tion·ism)Pronunciation: /pərˈfekSHəˌnizəm/Translate perfectionism | into German | into Italian Definition of perfectionism noun refusal to accept any standard short of perfection. Philosophy a doctrine holding that religious, moral, social, or political perfection is attainable, especially the theory that human moral or spiritual perfection should be or has been attained. perfectionism in other Oxford dictionaries Definition of perfectionism in the British & World English dictionary