Synonyms of unsubstantiated in English:

unsubstantiated


See US English definition of unsubstantiated

See UK English definition of unsubstantiated

adjective

1‘there were unsubstantiated allegations of serious misbehaviour’

SYNONYMS
unconfirmed, unsupported, uncorroborated, not backed up by evidence, unverified, unattested, unproven, not validated, untested
unfounded, ill-founded, groundless, baseless, without basis, without foundation, unjustified, unwarranted, unjustifiable, unreasonable
speculative, conjectural, assumed, presumed
questionable, open to question, disputable, debatable
unreliable, untrustworthy, dubious, doubtful, tenuous, spurious, suspect, flimsy, weak, nebulous, unsound, undependable
informal iffy
British informal dodgy
rare unestablished, suppositious, suppositive
ANTONYMS

well founded, undeniable