defective number

Imperfect Im*per"fect, a. [L. imperfectus: pref. im- not + perfectus perfect: cf. F imparfait, whence OE. imparfit. See {Perfect}.] 1. Not perfect; not complete in all its parts; wanting a part; deective; deficient. [1913 Webster]

Something he left imperfect in the state. --Shak. [1913 Webster]

Why, then, your other senses grow imperfect. --Shak. [1913 Webster]

2. Wanting in some elementary organ that is essential to successful or normal activity. [1913 Webster]

He . . . stammered like a child, or an amazed, imperfect person. --Jer. Taylor. [1913 Webster]

3. 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. [1913 Webster]

Nothing imperfect or deficient left Of all that he created. --Milton. [1913 Webster]

Then say not man's imperfect, Heaven in fault; Say rather, man's as perfect as he ought. --Pope. [1913 Webster]

{Imperfect arch}, an arch of less than a semicircle; a skew arch.

{Imperfect cadence} (Mus.), one not ending with the tonic, but with the dominant or some other chord; one not giving complete rest; a half close.

{Imperfect consonances} (Mus.), chords like the third and sixth, whose ratios are less simple than those of the fifth and forth.

{Imperfect flower} (Bot.), a flower wanting either stamens or pistils. --Gray.

{Imperfect interval} (Mus.), one a semitone less than perfect; as, an imperfect fifth.

{Imperfect number} (Math.), 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} (Math.), 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} (Gram.), a tense expressing past time and incomplete action. [1913 Webster]