A power-house is a term typically used to describe something or someone that is extremely powerful and dominating in its field. There are a number of synonyms that can be used to describe a power-house including dominant, influential, mighty, strong, potent, and commanding. These words all describe something or someone that is incredibly powerful and influential. Other synonyms may include heavyweights, leaders, and champions, all of which describe individuals or groups that are at the top of their game. Regardless of the synonym used, a power-house is something or someone that commands respect and is not to be taken lightly.