In online multiplayer gameplay, usally FPS (first person shooter), a 'blocker' is someone who blocks the only exit from a room or other confined space by standing, crouching or lying in the doorway in a way that prevents teammates players getting around them. Usually will gain a fast 'MOVE N00B BLOCKER!1!111' from other players, especially if their escape route from fire or grenades is blocked.
by Ass999 September 26, 2005