asperity – roughness of manner or of temper
(Pronounced a-speh-ruh-tee)
To remember the definition of the word asperity, use the following mnemonic:
A spare set of teeth (asperity) had been broken. Her usual calm tone suddenly turned harsh as she lost her temper.

Examples of asperity in a sentence
He'd never heard such asperity in her voice.
He was trying desperately to hide the asperity in his voice.
The asperity they received from the customer was completely uncalled for.