[1] : The Collaborative International Dictionary of English v.0.48

mightiness \might"iness\, 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

[2] : WordNet (r) 2.0

mightiness
     n : physical strength syn: might, power
see also:
might power 

Mightiness >> M Words
Mightiness, definition of term: Mightiness
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