CODEBOOK is a playable word

codebook Scrabble® Dictionary

noun
pl. codebooks
a book listing words and their coded equivalents
44 Playable Words can be made from "CODEBOOK"
   2-Letter Words (8 found)
   3-Letter Words (14 found)
   4-Letter Words (15 found)
   5-Letter Words (4 found)
   6-Letter Words (2 found)
   8-Letter Words (1 found)