sunhat vs sun hat

sunhat and sun hat both are nouns.

Word	Noun	Adjective	Verb	Adverb
sunhat	Yes	No	No	No
sun hat	Yes	No	No	No

As nouns, sunhat and sun hat are synonyms defined as:

sunhat and sun hat: a hat with a broad brim that protects the face from direct exposure to the sun

sunhat (noun)	sun hat (noun)
a hat with a broad brim that protects the face from direct exposure to the sun	a hat with a broad brim that protects the face from direct exposure to the sun