To cachinnate is to laugh loudly or laugh hard.(verb)
When you give a big, loud laugh at a joke, this is an example of a time when you cachinnate.
See cachinnate in Webster's New World College Dictionary
See cachinnate in American Heritage Dictionary 4
intransitive verb cach·in·nat·ed, cach·in·nat·ing, cach·in·nates
Origin: Latin cachinnāre, cachinnāt-
Origin: , of imitative origin.
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