UNREASONABLE definition: not reasonable or rational; acting at variance with or contrary to reason; not guided by reason or sound judgment; irrational. See examples of unreasonable used in a sentence.

The meaning of UNREASONABLE is not governed by or acting according to reason. How to use unreasonable in a sentence.

I find your attitude completely unreasonable. She divorced him on the grounds of unreasonable behaviour. If he expects you to do that, I think he's being completely unreasonable. I hope he doesn't …

1. not reasonable or rational; not guided by reason or sound judgment; irrational. 2. not in accordance with practical realities, as attitude or behavior; inappropriate. 3. excessive, immoderate, or exorbitant; …

Definition of unreasonable adjective from the Oxford Advanced Learner's Dictionary. not fair; expecting too much. The job was beginning to make unreasonable demands on his free time. The fees they …

Feb 24, 2026 · Adjective unreasonable (comparative more unreasonable, superlative most unreasonable) Without the ability to reason; unreasoning.

unreasonable meaning, definition, what is unreasonable: not fair or sensible: Learn more.

Unreasonable is an adjective that defines something which is not guided by or based on good sense, logic, or rationality; it can pertain to actions, expectations, demands, or behavior that is excessive, …

When someone's unreasonable, they're not using reason, or common sense, to make decisions or demands. Add the prefix un- to reasonable, "having sound judgment," and you get an adjective that's …

un•rea•son•a•ble /ʌnˈrizənəbəl, -ˈriznə-/ adj. not reasonable or rational; not guided by or showing reason or good judgment; irrational. too great; excessive, immoderate, or exorbitant: an unreasonable …