from The American Heritage® Dictionary of the English Language, 4th Edition
- intransitive v. To laugh hard, loudly, or convulsively; guffaw.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To laugh loudly, immoderately, or too often.
from The Century Dictionary and Cyclopedia
- To indulge in loud, continued laughter; to laugh immoderately.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- v. laugh loudly and in an unrestrained way
Latin cachinnāre, cachinnāt-, of imitative origin.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin cacchinō ("laugh aloud"), an onomatopoeia. (Wiktionary)