Synonyms to without grounds

groundless, baseless, bottomless, built on sand, chimerical, empty, flimsy, gratuitous, hypothetical, idle, ill-founded, illusory, imaginary, inconclusive, indecisive, not following, not proved, not well-founded, speculative, suppositional, tenuous, unascertained, unattested, unauthenticated, unbased, uncalled-for, uncertified, unconfirmed, uncorroborated, undemonstrated, undetermined, unestablished, unfixed, unfounded, ungrounded, unjustifiable, unjustified, unproved, unproven, unreasonable, unsettled, unshown, unsound, unsubstantiated, unsupportable, unsupported, unsupported by evidence, unsustainable, unsustained, untenable, untested, untried, unvalidated, unverified, unwarranted, vain, without basis, without foundation, absonant, contradictory, contrary to reason, fallacious, faulty, feeble, flawed, illogical, inauthentic, incongruous, inconsequent, inconsequential, inconsistent, indefinite, indeterminate, insubstantial, invalid, irrational, loose, nonscientific, open, paralogical, poor, reasonless, self