Unreasonable (adjective)

1. Not based on good sense or reason.
2. Excessive, disproportionate or unjustified.

Origin:

Late 16th century: from un-1 (expressing negation) + reasonable.

Examples:

1. His demand for a raise was unreasonable given his performance.
2. Her refusal to listen to reason was unreasonable.
3. The company's decision to fire all employees was considered unreasonable.
4. The judge ruled that the punishment was unreasonable.
5. The price of the item was deemed unreasonable for the quality offered.