Open English Wordnet
Nouns
Adjectives
(a)imperfectnot perfect; defective or inadequate“had only an imperfect understanding of his responsibilities”,
“imperfect mortals”,
“drainage here is imperfect” (s)fallible, frail, imperfect, weakwanting in moral strength, courage, or will; having the attributes of man as opposed to e.g. divine beings“I'm only a fallible human”,
“frail humanity”