tet-head Share definition Flag (aka tethead): A tet-head is one who has an overwhelming compulsion to play the game tetris. Dude, those tet-heads are really annoying! They ate all of my cheese while playing that damn game! tet-head by Edward "Tethead" Jonesifi January 6, 2008 0 0 Get merch Get the tet-head mug. Buy Now — $32.95 See more merch