FIX
FIXABLE
FIXATE
FIXATED
FIXATES
FIXATIF
FIXATIFS
FIXATING
FIXATION
FIXATIONS
FIXATIVE
FIXATIVES
FIXATURE
FIXATURES
FIXED
FIXEDLY
FIXEDNESS
FIXEDNESSES
FIXER
FIXERS
FIXES
FIXING
FIXINGS
FIXIT
FIXITIES
FIXITY
FIXIVE
FIXT
FIXTURE
FIXTURELESS
FIXTURES
FIXURE
FIXURES

33 words start with FIX.