Answer: rofl

AnswerCrossword Clue
ROFLIndication of amusement online that's probably not true IRL
ROFL"I'm hysterical!" in netspeak
ROFLTexter's response to a hilarious joke
ROFLNetizen's "That's hysterical!"
ROFLTexter's guffaw
ROFLModern response to hilarity
ROFL"That's too funny," to surfers
ROFLGuffaw in an AOL chat room