Cach′in‐na″tion (kăk′ĭn‐nā″shŭn), n. [L. cachinnatio, fr. cachinnare to laugh aloud, cf. Gr. καχάζειν.] Loud or immoderate laughter; — often a symptom of hysterical or maniacal affections.
Hideous grimaces... attended this unusual cachinnation.
Sir W. Scott.