imperfect

adj. not perfect; flawed, defective; of a tense which expresses ongoing action (Grammar)

n. (Grammar) imperfect tense, form which expresses an ongoing action; verb form in the imperfect tense

The imperfect tense, in the classical grammar of several Indo-European languages, denotes a past tense with an imperfective aspect. In English, it is referred to as the past continuous tense.The term originated with the Hebrew language because "imperfect" refers to an uncompleted or abandoned action.
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Noun
1. a tense of verbs used in describing action that is on-going
(synonym) progressive, progressive tense, imperfect tense, continuous tense
(hypernym) tense
(hyponym) present progressive, present progressive tense
Adjective
1. not perfect; defective or inadequate; "had only an imperfect understanding of his responsibilities"; "imperfect mortals"; "drainage here is imperfect"
(antonym) perfect
(similar) blemished, flawed
(see-also) blemished
(attribute) perfection, flawlessness, ne plus ultra
2. having the attributes of man as opposed to e.g. divine beings; "I'm only human"; "frail humanity"
(synonym) fallible, frail, weak
(similar) human

adj. imperfect, (Grammar) imperfect tense, form which expresses an ongoing action; verb form in the imperfect tense

(v. t.)
To make imperfect.
  

(n.)
The imperfect tense; or the form of a verb denoting the imperfect tense.
  

(a.)
Wanting in some elementary organ that is essential to successful or normal activity.
  

(a.)
Not perfect; not complete in all its parts; wanting a part; deective; deficient.
  

(a.)
Not fulfilling its design; not realizing an ideal; not conformed to a standard or rule; not satisfying the taste or conscience; esthetically or morally defective.