- not reasonable or rational; acting at variance with or contrary to reason; not guided by reason or sound judgment; irrational: an unreasonable person.
- not in accordance with practical realities, as attitude or behavior; inappropriate: His Bohemianism was an unreasonable way of life for one so rich.
- excessive, immoderate, or exorbitant; unconscionable: an unreasonable price; unreasonable demands.
- not having the faculty of reason.
- immoderate; excessiveunreasonable demands
- refusing to listen to reason
- lacking reason or judgment
adj.mid-14c., from un- (1) “not” + reasonable. Related: Unreasonably.