1) Might 2) Potency 1) Might 2) Power 3) Strength 
• (n.) The quality of being mighty; possession of might; power; greatness; high dignity. • (n.) Highness; excellency; -- with a possessive pronoun, a title of dignity; as, their high mightinesses.
Might'i·ness noun 1. The quality of being mighty; possession of might; power; greatness; high dignity. « How soon this mightiness meets misery.» Shak. 2. Highness; excellency; -- with a possessive pronoun, a title of dignity; as, their high mightinesses...