ill-founded
adjective
• (especially of an idea or belief) not based on fact or reliable evidence.
• "ill-founded criticism"
Similar:
baseless,
groundless,
without foundation,
foundationless,
without basis,
unjustified,
unsupported,
unsubstantiated,
unproven,
unverified,
uncorroborated,
unconfirmed,
unauthenticated,
not backed up by evidence,
speculative,
conjectural,
unsound,
unreliable,
questionable,
misinformed,
misguided,
spurious,
trumped-up,
