n. 大笑, 哄笑, 放纵地笑

[医] 癔病狂笑, 歇斯底里性狂笑

[ noun ]
loud convulsive laughter
<noun.communication>

Cachinnation \Cach`in*na"tion\ (k[a^]k`[i^]n*n[=a]"sh[u^]n), n.
[L. cachinnatio, fr. cachinnare to laugh aloud, cf. Gr.
kacha`zein.]
Loud or immoderate laughter; -- often a symptom of hysterical
or maniacal affections.

Hideous grimaces . . . attended this unusual
cachinnation. --Sir W.
Scott.