sun vs sunshine

sun and sunshine both are nouns.

Word	Noun	Adjective	Verb	Adverb
sun	Yes	No	Yes	No
sunshine	Yes	No	No	No

As nouns, sun and sunshine are synonyms defined as:

Other synonyms of sun include sunlight.

sun (noun)	sunshine (noun)
any star around which a planetary system revolves	the quality of being cheerful and dispelling gloom
the star that is the source of light and heat for the planets in the solar system	the rays of the sun
a person considered as a source of warmth or energy or glory etc	moderate weather; suitable for outdoor activities
the rays of the sun

sun (verb)	sunshine (verb)
expose one's body to the sun
expose to the rays of the sun or affect by exposure to the sun