Synonyms to not well-founded

baseless, bottomless, built on sand, empty, false, gratuitous, groundless, idle, ill-founded, indefensible, needless, pointless, reasonless, senseless, unbased, uncalled-for, unfounded, ungrounded, unjustifiable, unnecessary, unneeded, unsolid, unsupportable, unsupported, unsustainable, unsustained, untenable, unwarranted, vain, without basis, without foundation, wrong, chimerical, flimsy, hypothetical, illusory, imaginary, inconclusive, indecisive, not following, not proved, speculative, suppositional, tenuous, unascertained, unattested, unauthenticated, uncertified, unconfirmed, uncorroborated, undemonstrated, undetermined, unestablished, unfixed, unjustified, unproved, unproven, unreasonable, unsettled, unshown, unsound, unsubstantiated, unsupported by evidence, untested, untried, unvalidated, unverified, without f