unwarrantable

Etymology

From un- + warrantable.

adj

1. Not warrantable; indefensible; not vindicable; not justifiable
   Another thing, that engageth our affections to unwarrantable conclusions, and is therefore fatal to Science; is our doting on Antiquity, and the opinions of our Fathers. 1661, Joseph Glanvill, chapter 15, in The Vanity of Dogmatizing, London: Henry Eversden, pages 136–137
   […] the taking up arms, merely to enforce the repeal of a pecuniary law, seems as unwarrantable by the divine law, and as repugnant to human feelings, as the taking up arms to enforce the obedience thereto. 1776, Thomas Paine, “The Necessity of Independancy”, in Common Sense, Philadelphia, page 70
   ‘[…] Don’t persist, sir! or else I shall be obliged to inform my master of your designs; and he’ll take measures to secure his house and its inmates from any such unwarrantable intrusions!’ 1847, Emily Brontë, chapter 14, in Wuthering Heights