mightily in WordNet English dictionary

1. (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"
   mighty  mightily  powerful  right  mighty  mightily  powerful  right 
   
2. powerfully or vigorously
   "he strove mightily to achieve a better position in life"
   mightily  mightily