1. (noun) the time in the evening at which the sun begins to fall below the horizon

• sundown

1. (noun) the time in the evening at which the sun begins to fall below the horizon

• hour
• time of day

2. (noun) atmospheric phenomena accompanying the daily disappearance of the sun

• atmospheric phenomenon

3. (noun) the daily event of the sun sinking below the horizon

• periodic event
• recurrent event

1. (adjective) of a declining industry or technology

• old

2. (adjective) providing for termination

• last

1. (noun) the time in the evening at which the sun begins to fall below the horizon

• aurora
• break of day
• break of the day
• cockcrow
• dawn
• dawning
• daybreak
• dayspring
• first light
• morning
• sunrise
• sunup