1 : roughness of manner or of temper : harshness of behavior or speech that expresses bitterness or anger
2 : rigor, severity
3 : roughness of surface : unevenness; also : a tiny projection from a surface
4 : roughness of sound
1 : His asperity made him hard to approach and harder to converse with, especially when asking questions about the past.
2 : The asperity of her confusion left her frightned, and we couldn’t get any answers from her.
Okay, I’d say this is another word in case you run into it in reading. Especially since it has many uses, and not all of them are easy to pull from context. I think I’ve ran into examples of the second definition, but I can’t say anything for which use is common vs rare.