VASTLY is a playable word

vastly Scrabble® Dictionary

adverb
to a vast extent or degree
42 Playable Words can be made from "VASTLY"
   2-Letter Words (7 found)
   3-Letter Words (18 found)
   4-Letter Words (12 found)
   5-Letter Words (4 found)
   6-Letter Words (1 found)