risible (adj.) Look up risible at Dictionary.com
1550s, "given to laughter," from Middle French risible (14c.) and directly from Late Latin risibilis "laughable, able to laugh," from Latin risus, past participle of ridere "to laugh," a word which, according to de Vaan, "has no good PIE etymology." Meaning "capable of exciting laughter, comical" is from 1727.