1. The hardening of something by using heat in order to produce more strength or more solidness: The blacksmith used tempering in order to make the metal for the bridles of the horses strong and durable.
2. The situation of making something more balanced or less intense: The tempering of Monroe's extreme excitement about climbing up Mt. Everest was made clear to him after learning that he would have to lose quite a bit of weight and do workouts at the fitness studio three times week for at least a year.