'asperser' ultimately derives from Latin: from the verb 'aspergere' (past participle 'aspersus'), formed from ad- 'to/toward' + spargere 'to scatter, to sprinkle'.

'asperse' entered English via Old French/Medieval Latin (Old French forms like 'asperser' or Medieval Latin 'aspersare'); the noun 'asperser' developed in English to denote one who asperges or one who maligns.

Originally related to 'sprinkle' or 'besprinkle' (literally to scatter or sprinkle upon), the term developed a figurative sense of 'besmirch' or 'attack someone's reputation' and now commonly means to slander or defame.