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.
Person 1: (something funny on an instant messenger)
Person 2: hahaha
Person 2: ialat
by Poopydoo December 20, 2005
Get a ialat mug for your cousin Beatrix.
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.
Person 1: I just stepped on some cinnamon toast crunch, now I'm a cereal killer

Person 2: ialat
by TheCompassMan October 11, 2014
Get a IALAT mug for your mama Jovana.