This stands for "I actually laughed at that". It is an alternate version of lol or rofl and is used in certain situations when something funny is said, but saying lol would cheapen the effect of it.
by Poopydoo December 21, 2005
IALAT or ialat is an acronym for "I Actually Laughed At That". This is used to let someone know just how funny a text, message, or email was.
by TheCompassMan October 11, 2014