#1 mightily r. powerfully or vigorously; "he strove mightily to achieve a better position in life". wn
#2 mightily r. [mighty, powerful, right] (Southern regional intensive) very; to a great degree; "the baby is mighty cute"; "he's mighty tired"; "it is powerful humid"; "that boy is powerful big now"; "they have a right nice place"; "they rejoiced mightily". wn
vizzz