Synonyms to built on sand

baseless, bottomless, empty, false, gratuitous, groundless, idle, ill-founded, indefensible, needless, not well-founded, 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