Asperity

Definition:

(n.) Roughness of surface; unevenness; -- opposed to smoothness.
(n.) Roughness or harshness of sound; that quality which grates upon the ear; raucity.
(n.) Roughness to the taste; sourness; tartness.
(n.) Moral roughness; roughness of manner; severity; crabbedness; harshness; -- opposed to mildness.
(n.) Sharpness; disagreeableness; difficulty.

Compare asperity with other words:

ascetic vs. asperity