ambiguous
cost-plus
equivocal
inconclusive
indeterminable
open-ended
racemose
undeterminable
abstract
accidental
adventitious
aleatoric
aleatory
amorphic
amorphous
anarchic
baggy
bland
blind
blobby
blurred
blurry
broad
casual
causeless
chance
chancy
chaotic
characterless
clear as mud
cloudy
collective
confused
contingent
dark
destinal
dicey
dim
disordered
disorderly
fatal
fatidic
featureless
fluky
foggy
formless
fortuitous
fuzzy
general
generalized
generic
hazy
hit-or-miss
iffy
ill-defined
imprecise
inaccurate
inchoate
approximate
changeable
contradictory
determinate
doubtful
elusive
fragmentary
incomplete
indefinite
indistinct
nebulous
uncertain
undecided
undefined
undetermined
unintelligible
unstable