adj. 25B6; adjective
an unjustifiable extravagance : INDEFENSIBLE, inexcusable, unforgivable, unpardonable, uncalled for, without justification, unwarrantable; excessive, immoderate.
an unjustifiable slur on his character : GROUNDLESS, unfounded, baseless, unsubstantiated, unconfirmed, uncorroborated.
reasonable.