baseless
/ˈbeɪsləs/
adjective
Without foundation in fact.
baseless allegations
groundless,unfounded,unsubstantiated,unproven,unsupported,uncorroborated,untested,unconfirmed,unverified,unattested,unjustified,unwarranted,foundationless,ill-founded,without basis,without foundation,not backed up by evidence