I. -sh(ə)nə̇st noun
( -s )
Etymology: perfection (I) + -ist
1. : an adherent of perfectionism: as
a. : one who believes in the ethical or spiritual perfectibility of mankind
a Puritan perfectionist — Saturday Review
b. usually capitalized : a member of the original Oneida Community practicing perfectionism
c. : one who claims to have attained moral perfection or sinlessness
2. : one that demands or works to achieve perfection
they are perfectionists and will either have the best or nothing at all — Nancy Mitford
a perfectionist , he rehearsed one scene … 50 times — Time
II. adjective
also per·fec·tion·is·tic pə(r)|fekshə|nistik, -tēk
: of, relating to, or characterized by perfection or perfectionism