The Collaborative International Dictionary of English v.0.48:
Asperity \As*per"i*ty\, n.; pl. Asperities. [L. asperitas, fr.
asper rough: cf. F. asp['e]rit['e].]
1. Roughness of surface; unevenness; -- opposed to
smoothness. "The asperities of dry bodies." --Boyle.
2. Roughness or harshness of sound; that quality which grates
upon the ear; raucity.
3. Roughness to the taste; sourness; tartness.
4. Moral roughness; roughness of manner; severity;
crabbedness; harshness; -- opposed to mildness.
"Asperity of character." --Landor.
It is no very cynical asperity not to confess
obligations where no benefit has been received.
5. Sharpness; disagreeableness; difficulty.
The acclivities and asperities of duty. --Barrow.
Syn: Acrimony; moroseness; crabbedness; harshness; sourness;
tartness. See Acrimony.