controversial
plausible
at issue
confutable
conjectural
contestable
controvertible
debatable
deniable
disputable
doubtable
doubtful
dubious
dubitable
iffy
in dispute
in doubt
in dubio
in question
mistakable
moot
open to doubt
open to question
problematic
questionable
refutable
speculative
suppositional
suspect
suspicious
uncertain
50-50
all-or-nothing
allochthonous
base/base
chicken-and-egg
either-or
either/or
feel
forfeiture-by-wrongdoing
forty-seventh
in-stride
lose-lose
once-in-a-lifetime
open-and-shut
take-it-or-leave-it
undecidable
unrepaired
vulgarest
well-based