blemish

a mark or flaw that spoils the appearance of something (especially on a person's body)

Any mark of deformity or injury, whether physical or moral; anything that diminishes beauty, or renders imperfect that which is otherwise well formed; that which impairs reputation.

mar or spoil the appearance of

mar or impair with a flaw

add a flaw or blemish to; make imperfect or defective

To mark with deformity; to injure or impair, as anything which is well formed, or excellent; to mar, or make defective, either the body or mind.