Meaning of imperfect

(adj) not perfect; defective or inadequate; "had only an imperfect understanding of his responsibilities"; "imperfect mortals"; "drainage here is imperfect"

wanting 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"

(noun) a tense of verbs used in describing action that is on-going