Perfectionism, in psychology, is a belief that perfection can and should be attained. In its pathological form, it is a belief that anything less than perfect is unacceptable. At pathological levels, this is considered an unhealthy belief
a disposition to feel that anything less than perfect is unacceptable; "his perfectionism seemed excessive to his students"
Someone who is a perfectionist refuses to do or accept anything that is not as good as it could possibly be. someone who is not satisfied with anything unless it is completely perfect