BUILDUP is a playable word

buildup Scrabble® Dictionary

noun
pl. buildups
an accumulation
27 Playable Words can be made from "BUILDUP"
   2-Letter Words (5 found)
   3-Letter Words (16 found)
   4-Letter Words (3 found)
   5-Letter Words (1 found)
   7-Letter Words (2 found)