What is Imperfect?

Imperfect definition and meaning on Dictionary terms:
of, relating to, or characterized by defects or weaknesses: imperfect vision.
not perfect; lacking completeness: imperfect knowledge.
Grammar. noting action or state still in process at some temporal point of reference, particularly in the past.
Law. being without legal effect or support; unenforceable.

Botany. (of a flower) diclinous.
Music. of or relating to the interval of a major or minor third or sixth.Compare perfect(def 13a).

noun Grammar.
the imperfect tense.
another verb formation or construction with imperfect meaning.

a form in the imperfect, as Latin port?bam,