Dusk
Part of speech: noun
Definition: A period of time occurring at the end of the day during which the sun sets.
Part of speech: verb
Definition: to begin to lose light or whiteness; to grow dusk
Example sentence: 'Anthems to the Welkin at Dusk,' that's my big Emperor album.
Sunset
Part of speech: noun
Definition: The time of day when the sun disappears below the western horizon.The changes in color of the sky at sunset.The final period of the life of a person or thing.(attributively) Of or relating to the final period of the life of a person or thing.(attributively) Having a set termination date.