Lol

Acronym for "laugh out loud."

Formerly used accordingly, but now used when you have nothing to say or don't really care.
Used in verbal speech (pronounced 'L O L') almost exclusively by brain-dead Starbucks-drinking cellphone-addicted teenage/early twenties girls (or gay guys) that drive light blue Japanese compacts and lose the ability to perform basic human functions when their phone dies or Snapchat is unavailable.

(Tiffany) "I think I will post my breakfast onto my Instagram."
(No-life follower 1) "lol"
(No-life follower 2) "lol omg"
(No-life follower 3) "lol that's so interesting"
(A thousand other random followers that don't really care and don't even know who they are following) "lol"