Definition from Wiktionary, the free dictionary
cachinnation (plural cachinnations)
- Convulsive, loud laughter.
1920, Peter B. Kyne, “V”, in The Understanding Heart:
- His shrill, mirthless cachinnation followed Monica as she headed up-hill.
- 1928, H. P. Lovecraft, The Dunwich Horror,
- After midnight their shrill notes burst into a kind of pandemoniac cachinnation which filled all the countryside, and not until dawn did they finally quiet down.