asperation n.

c. 1200, asprete "hardship," from Old French asperité "difficulty, painful situation, harsh treatment" (12c., Modern French âpreté), a figurative use, from Latin asperitatem (nominative asperitas) "roughness," from asper "rough, harsh," which is of unknown origin. The Latin adjective was used also of sour wine, bad weather, and hard times. The figurative meaning "harshness of feeling" in English is attested from 1660s; the literal sense of "roughness of surface" is from early 15c.

"make rough," 1650s, from Latin asperatus, past participle of asperare "to roughen, make rough," figuratively "exasperate," from asper "rough" (see asperity). Related: Asperated; asperating.