Deformity, n.; pl. Deformities.
Etymology: [L. deformitas, fr. deformis: cf. OF. deformeté, deformité, F. difformité. See Deform, v. & a., and cf. Disformity.]
1. The state of being deformed; want of proper form or symmetry; any unnatural form or shape; distortion; irregularity of shape or features; ugliness. To make an envious mountain on my back, Where sits deformity to mock my body. Shak.
2. Anything that destroys beauty, grace, or propriety; irregularity; absurdity; gross deviation from other or the established laws of propriety; as, deformity in an edifice; deformity of character. Confounded, that her Maker's eyes Should look so near upon her foul deformities. Milton.
Shades of meaning
Fernald has no entry of its own for deformity; he lists it under blemish.
He lists it without comment; the entries above explain its neighbors.