1590s, "to laugh loudly," frequentative of Middle English chukken "make a clucking noise" (late 14c.), of imitative origin. Meaning shifted to "laugh in a suppressed or covert way, express inward satisfaction by subdued laughter" by 1803. Related: Chuckled; chuckling.
1550s, "given to laughter," from 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 "laughable, capable of exciting laughter, comical" is by 1727. Related: Risibility.
"loud laughter," 1620s, from Latin cachinnationem (nominative cachinnatio) "violent laughter, excessive laughter," noun of action from past-participle stem of cachinnare "to laugh immoderately or loudly," of imitative origin. Compare Sanskrit kakhati "laughs," Greek kakhazein "to laugh loudly," Old High German kachazzen, English cackle, Armenian xaxanc'.
also heehaw, attested by 1815 (as Hiu Haw), probably imitative of sound of donkey's bray (compare French hinham). As "a loud laugh" from 1843.