contrary to reason; unreasonable; irrational
Fixed expression used to describe actions, arguments, or demands that go against logic or common sense. Often used in formal or critical contexts.
Such a demand is contrary to reason.
His argument was unreasonable.
不合理 is a noun/adjective meaning irrational or illogical, often used in formal or academic contexts. 道理に外れた is a phrase that functions attributively or predicatively.
A fixed phrase composed of 道理 (reason, logic) + に (particle) + 外れた (past/attributive form of 外れる, to deviate). Literally 'deviated from reason'.