Imperfection, n.
Etymology: [L. imperfectio: cf. F. imperfection. See Imperfect, a.]
The quality or condition of being imperfect; want of perfection; incompleteness; deficiency; fault or blemish. Sent to my account With all my imperfections on my head. Shak.
Syn. -- Defect; deficiency; incompleteness; fault; failing; weakness; frailty; foible; blemish; vice.
Shades of meaning
Fernald has no entry of its own for imperfection; he lists it under blemish.
He lists it without comment; the entries above explain its neighbors.