PENTAD is a playable word

pentad Scrabble® Dictionary

noun
pl. pentads
a group of five
74 Playable Words can be made from "PENTAD"
   2-Letter Words (15 found)
   3-Letter Words (30 found)
   4-Letter Words (19 found)
   5-Letter Words (7 found)
   6-Letter Words (3 found)