- the setting or descent of the sun below the horizon in the evening.
- the atmospheric and scenic phenomena accompanying this.
- the time when the sun sets.
- the close or final stage of any period.
- (of an industry, technology, etc.) old; declining: sunset industries.
- of, relating to, or characteristic of a sunset law: to add sunset restrictions to a bill.
- the daily disappearance of the sun below the horizon
- the atmospheric phenomena accompanying this disappearance
- the time at which the sun sets at a particular locality
- the final stage or closing period, as of a person's life
