The term 'over-balancing' refers to an excessive or uncontrolled movement in a particular direction. An antonym for over-balancing is balance or equilibrium, which is a state of stability and harmoniousness. Other antonyms for over-balancing could include stability, steadiness, poise, or composure. These words indicate a state of harmony and control, where movement and actions are balanced and in proportion. Over-balancing can cause chaos and instability, while the opposite represents calmness and order. It's important to maintain balance in one's life, whether it's physical, mental or emotional, and avoid over-balancing in any direction.