CEPHEID is a playable word

cepheid Scrabble® Dictionary

noun
pl. cepheids
a giant star
56 Playable Words can be made from "CEPHEID"
   2-Letter Words (8 found)
   3-Letter Words (22 found)
   4-Letter Words (18 found)
   5-Letter Words (5 found)
   6-Letter Words (2 found)
   7-Letter Words (1 found)