The physical manifestation of hilarity, aka a fit of giggles, that leaves you breathless, unable to make any sound, but shaking and rocking in your seat with laughter. Nothing to do with Quaker comedians. Example: She was laughing so hard, the mirthquake was an 8.2 on the Bill Hicks Scale.
MIRTHQUAKE
Meaning of MIRTHQUAKE in English
Slang English vocab. Английский сленговый словарь. 2012