'Mightiness' definitions:

Definition of 'mightiness'

From: WordNet
noun
Physical strength [syn: might, mightiness, power]

Definition of 'Mightiness'

From: GCIDE
  • Mightiness \Might"i*ness\, n.
  • 1. The quality of being mighty; possession of might; power; greatness; high dignity. [1913 Webster]
  • How soon this mightiness meets misery. --Shak. [1913 Webster]
  • 2. Highness; excellency; -- with a possessive pronoun, a title of dignity; as, their high mightinesses. [1913 Webster]