SUBBLOCKS is a playable word

subblock Scrabble® Dictionary

noun
pl. subblocks
a subdivision of a block
101 Playable Words can be made from "SUBBLOCKS"
   2-Letter Words (6 found)
   3-Letter Words (19 found)
   6-Letter Words (3 found)
   8-Letter Words (1 found)
   9-Letter Words (1 found)