Answer:

LOL

AnswerCrossword Clue
LOLComputer expression
LOLYukking it up in cyberspace
LOLPalindromic 2011 OED inclusion
LOLCyberchuckle
LOLMiley Cyrus movie starring Demi Moore (yes, this is a thing; it shouldn't be, but it is)
LOL"Good one, fellow Redditor!"
LOLChat room guffaw
LOLChatroom chortling
LOLChat-room chuckle
LOLTexter's titter
LOLReaction not as strong as ROFL
LOLChatroom chortle
LOL"u r funny!"
LOLOn-line guffaw
LOLTexter's chuckle
LOLTexting guffaw
LOL"U R a riot!"
LOLTexted "ha ha"
LOLOnline shorthand in reply to a joke
LOLChat-room guffaw
LOLOnline guffaw
LOLFacebook chuckle
LOL"Ha!," in texts
LOLReaction to a meme, maybe
LOL"OMG ur a riot!"
LOLChat room chuckle
LOLOnline chuckle
LOLOnline haw-haw
LOLCyberguffaw
LOLE-mail outburst
LOLOnline "Ha-ha!"
LOLOnline "That's funny!"
LOLBit of high-tech amusement
LOLChat room "That's a riot!"
LOLCyberspace snicker
LOLIM chuckle
LOLWisecrack response, in modern shorthand
LOLCybercackle
LOLCyberchortle
LOLCyberroar