baseless empty feeble flimsy groundless idle ill-founded inconclusive indecisive insubstantial not following not proved poor unascertained unattested unauthenticated unbased uncertified unconfirmed uncorroborated undemonstrated undetermined unestablished unfixed unfounded ungrounded unproved unproven unrigorous unsettled unshown unsound unsubstantial unsubstantiated unsupportable unsupported unsupported by evidence unsustainable untenable untested untried unvalidated unverified unwarranted vain weak without basis without foundation without grounds