căchinnātĭo — Lewis & Short
căchinnātĭo, ōnis, f.id.,
I a violent laughing, immoderate laughter:
sine ullā suspitione nimiae suspitionis,Auct. Her. 3, 14, 25:
ut si ridere concessum sit, vituperetur tamen cachinnatio,Cic. Tusc. 4, 31, 66.