Someone who makes excuses not to go to previously planned engagements; someone who blows people off to do other things or because they don't "feel" like it; an unreliable person. Comes from the word flake pronounced wrong one day.

Flacker is a name that you call someone who slacks intensly. Flacker would mean a Freakin' slacker.

1.) A fucking slacker.
2.) One who flacks.

someone who is using flash hacks in Counterstrike.