‖pl. [ L. imperfecti imperfect. ] (Bot.) A heterogenous phylum of fungi which lack a sexual phase, or of which the sexual phase is not known. Some undoubtedly represent the conidium stages of various Ascomycetes. It is not considered a natural phylum, and is also called the Deuteromycota. The group is divided into the orders Sphæropsidales, Melanconiales, and Moniliales. It includes the genera Penicillium and Aspergillus, which reproduce asexually by means of conidia. [ Webster 1913 Suppl. +PJC ]

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 ]

n. (Gram.) The imperfect tense; or the form of a verb denoting the imperfect tense. [ 1913 Webster ]

v. t. To make imperfect. [ Obs. ] [ 1913 Webster ]

n. The state or quality of being imperfectible. [ R. ] [ 1913 Webster ]

a. Incapable of being made perfect. [ R. ] [ 1913 Webster ]

n. [ L. imperfectio: cf. F. imperfection. See Imperfect, a. ] The quality or condition of being imperfect; lack of perfection; incompleteness; deficiency; fault or blemish. [ 1913 Webster ]

Sent to my account
With all my imperfections on my head. Shak.

Syn. -- Defect; deficiency; incompleteness; fault; failing; weakness; frailty; foible; blemish; vice. [ 1913 Webster ]

n. The state of being imperfect. [ 1913 Webster ]

a. & n. [ Pref. preter- + imperfect. ] (Gram.) Old name of the tense also called imperfect. [ 1913 Webster ]