imperfect

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Not perfect.
2. adj. Grammar Of or being the tense of a verb that shows, usually in the past, an action or a condition as incomplete, continuous, or coincident with another action.
3. adj. Botany Having either stamens or a pistil only. Used of a flower.
4. adj. Law Not legally enforceable: an imperfect contract.
5. n. A piece of merchandise having a minor flaw that does not impair its use, usually sold at a discount.
6. n. Grammar The imperfect tense.
7. n. Grammar A verb in the imperfect tense.

Century Dictionary and Cyclopedia

1. Not perfect; lacking completeness, correctness, or excellence; falling short of a standard or ideal; defective; incomplete: as, an imperfect copy of a book; imperfect vision.
2. Characterized by or subject to defects; not completely good; frail; inadequate.
3. In gram., designating incomplete or continuous action, or action or condition conceived as in process when something else takes place, as in Latin amabat, French aimait, Greek ε%27λνε, as distinguished from the simple past forms (aoristic), without further implication, amavit, aima, ε%27λνσε. In the languages most familiar to us only past time is thus distinguished; and hence the English simple past tense, or preterit, is often, but improperly, called imperfect.
4. In music. See the phrases below.
5. Unjust; unfair.
6. Weak, erring.
7. n. In grammar, an imperfect tense; a past continuous tense.
8. To render imperfect.

Wiktionary

1. adj. Not perfect
2. adj. botany unisexual: having either male (with stamens) or female (with pistil) flowers, but not with both.
3. adj. taxonomy Known or expected to be polyphyletic, as of a form taxon.
4. n. Something having a minor flaw
5. n. grammar A tense of verbs used in describing a past action that is incomplete or continuous.

GNU Webster's 1913

1. adj. Not perfect; not complete in all its parts; wanting a part; deective; deficient.
2. adj. Wanting in some elementary organ that is essential to successful or normal activity.
3. adj. 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.
4. n. (Gram.) The imperfect tense; or the form of verb denoting the imperfect tense.
5. v. obsolete To make imperfect.

WordNet 3.0

1. n. a tense of verbs used in describing action that is on-going
2. adj. wanting in moral strength, courage, or will; having the attributes of man as opposed to e.g. divine beings
3. adj. not perfect; defective or inadequate