Webster's Revised Unabridged Dictionary · 1913

Imperfect

Imperfect , adjective

[Latin imperfectus: pref. im- not + perfectus perfect: compare F imparfait, whence Old English imparfit. See Perfect.]

1.
Not perfect; not complete in all its parts; wanting a part; defective; deficient.
Something he left imperfect in the state. — Shakespeare
Why, then, your other senses grow imperfect. — Shakespeare
2.
Wanting in some elementary organ that is essential to successful or normal activity.
He... stammered like a child, or an amazed, imperfect person. — Jer. Taylor
3.
Not fulfilling its design; not realizing an ideal; not conformed to a standard or rule; not satisfying the taste or conscience; aesthetically or morally defective.
Nothing imperfect or deficient left Of all that he created. — Milton
Then say not man's imperfect, Heaven in fault; Say rather, man's as perfect as he ought. — Pope
Collocations (9)
Imperfect arch , an arch of less than a semicircle; a skew arch.
Imperfect cadence (Music) , one not ending with the tonic, but with the dominant or some other chord; one not giving complete rest; a half close.
Imperfect consonances (Music) , chords like the third and sixth, whose ratios are less simple than those of the fifth and forth.
Imperfect flower (Botany) , a flower wanting either stamens or pistils. — Gray
Imperfect interval (Music) , one a semitone less than perfect; as, an imperfect fifth.
Imperfect number (Mathematics) , a number either greater or less than the sum of its several divisors; in the former case, it is called also a defective number; in the latter, an abundant number.
Imperfect obligations (Law) , obligations as of charity or gratitude, which cannot be enforced by law.
Imperfect power (Mathematics) , a number which can not be produced by taking any whole number or vulgar fraction, as a factor, the number of times indicated by the power; thus, 9 is a perfect square, but an imperfect cube.
Imperfect tense (Grammar) , a tense expressing past time and incomplete action.

Imperfect (im*pẽr"fekt) , noun

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

Imperfect , transitive verb

To make imperfect. [Obsolete]