IPA: /æˈspɛrɪti/
KK: /æspəˈrɪti/
A quality of being harsh or severe in tone, manner, or surface texture.
The asperity in his voice made it clear that he was not pleased with the decision.
Asperity is formed from "asper" (from Latin, meaning rough or harsh) and the suffix "-ity" (meaning the state or quality of). The word describes the quality of being rough or harsh, often in tone or manner.
Think of 'roughness' ('asper') to remember that 'asperity' refers to a state of being harsh or severe.