/ Dictionary / Index M mightily: Meaning and Definition of Find definitions for: might•i•ly Pronunciation: (mīt'l-ē), [key] — adv. in a mighty manner; powerfully or vigorously. to a great extent or degree; very much: to desire something mightily. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mightily (Thesaurus) might mightn't Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language