sunset >> ˈsʌnsɛt
Definition: [noun] the time in the evening when the sun disappears or daylight fades.
Example: sunset was still a couple of hours away
Definition: [adjective] denoting a legal provision under which a programme, agency, regulation, etc., is automatically terminated at the end of a fixed period unless renewed by legislative action.
Example: the bill will have a two-year sunset clause, so the decision will need to be revisited after the next election
Definition: [verb] (of a programme, agency, regulation, etc.) expire or be terminated automatically at the end of a fixed period unless renewed by legislative action.
Example: the tax cut will sunset after three years unless lawmakers extend it