ball out verb4 •(slang) To play or perform extremely well.The Lakers were behind the whole game until they started balling out in the last quarter. •(slang) To spend extravagant amounts of money (especially at a casino or nightclub); to act as a baller.I'm not going to tell you how much I lost last night—let's just say I balled out. •To move a plant with its rootball attached. •To plug a hole using a ball sealer. formsballed out · balling out · balls out