sunhat vs sunbonnet

sunhat and sunbonnet both are nouns.

Word	Noun	Adjective	Verb	Adverb
sunhat	Yes	No	No	No
sunbonnet	Yes	No	No	No

As nouns, sunbonnet is a hyponym of sunhat; that is, sunbonnet is a word with a more specific, narrower meaning than sunhat:

sunhat: a hat with a broad brim that protects the face from direct exposure to the sun
sunbonnet: a large bonnet that shades the face; worn by girls and women

Other hyponyms of sunhat include pith hat, pith helmet, sun helmet, topee, topi.

sunhat (noun)	sunbonnet (noun)
a hat with a broad brim that protects the face from direct exposure to the sun	a large bonnet that shades the face; worn by girls and women