Immoderate, excessive; unreasonable; intemperate. att hofelæs (quot. 1175), immoderately.

Of a person or animal: not having the faculty of reason, incapable of reasoning. Also: belonging to or characteristic of such a person or animal.

In mod. use, of alleged reasons, fears, etc.: Perversely or irrationally imagined.

Devoid of reason, unreasonable, groundless.

Not based on reason or reasons; not supported by any reason.

Without foundation: baseless, groundless.

Contrary or opposed to logic; illogical; not based upon reason or sound judgement. More neutrally: (Philosophy and Psychology) not determined or…

Destitute of foundation, authority, or support; having no real cause or reason; unfounded.

Contrary to or not in accordance with reason; unreasonable, utterly illogical, absurd.

Not reasonable (in various senses).

Absurd, illogical. Cf. paradoxal, adj. 2, paradoxical, adj.

Not in accordance with reason; unreasonable; = irrational, adj. 2.

Of a person or animal: without reason, good sense, or sound judgement; irrational.

Marked by lack of reason or fitness. Obsolete.

(See quot. 1825.) dialect.

Of, relating to, or characterized by aberration; eccentric, irrational, unsound. Also: aberrant, abnormal, diverging from the norm.

Not rational; irrational.

Characterized by irrationalism; contrary to reason; illogical.

colloquial (now chiefly Australian). a bit hot: (of behaviour, an action, etc.) somewhat unreasonable or excessive. Cf. red-hot, adj. 4.

That does not purport to be rational; not governed by the laws of reason, non-rational. Also elliptical as n.