The phrase 'holds off' usually refers to the act of delaying or stopping something from happening. The opposite of 'holds off' is 'accelerates' or 'speeds up'. If someone is trying to hold off a decision, then they might be hesitant or indecisive. In contrast, if they are accelerating a decision, then they may be impulsive or rash. Similarly, if someone is trying to hold off an attack, then they are being defensive, and the opposite of this would be to launch an attack or initiate an action. Overall, the antonyms of 'holds off' include accelerate, initiate, begin, and launch.