Laughter without apparent cause, often observed in schizophrenia. ... Origin: L. Cachinno, to laugh immoderately and loudly ... (05 Mar 2000) ... Found on http://www.encyclo.co.uk/local/20973
Cach`in·na'tion (kăk`ĭn*nā'shŭn) noun [ Latin cachinnatio , from cachinnare to laugh aloud, confer Greek kacha`zein .] Loud or immoderate laughter; -- often a symptom of hysterical or maniacal affections. « Hideous grimaces . . . attended this un... Found on http://www.encyclo.co.uk/webster/C/3