uncorroborated

flimsy gratuitous groundless unfounded unjustifiable unjustified unsubstantiated unsupported untenable unwarranted

bottomless foundationless reasonless unconfirmed ungrounded

called-for justified proven reasonable warranted

based

informal personal

off the record private unconfirmed unsanctioned

authoritative authorized confirmed official

debatable dubious unsupported

arguable controversial disputable doubtful dubitable fishy hard to believe iffy indefinite open to doubt open to question suspect suspicious uncertain unconfirmed

certain sure