Untenable

Adjective

 * 1) Not able to be held, as of an opinion or position; unholdable, indefensible.

Adverbs for Untenable
fallibly; unreliably; inaccurately; insubstantially; absolutely; manifestly; carelessly; inconclusively; fallaciously; ultimately; obviously; absurdly; hopelessly; wholly; ridiculously; laughably.

Thesaurus
aidless, baseless, defenseless, empty, exceptionable, fatherless, faulty, flawed, friendless, groundless, guideless, helpless, idle, ill-founded, illogical, implausible, impossible, inadmissible, indefensible, inexpiable, insupportable, intolerable, leaderless, motherless, objectionable, pregnable, specious, unacceptable, unbased, undesirable, unforgivable, unfounded, unfriended, ungrounded, unjustifiable, unjustified, unpardonable, unprotected, unreasonable, unsound, unsuitable, unsupportable, unsupported, unsustainable, unsustained, unwarranted, vain, vulnerable, weak, without basis, without foundation