sun lamp vs sun-ray lamp

sun lamp and sun-ray lamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
sun lamp	Yes	No	No	No
sun-ray lamp	Yes	No	No	No

As nouns, sun lamp and sun-ray lamp are synonyms defined as:

sun lamp and sun-ray lamp: a mercury-vapor lamp used in medical or cosmetic treatments

Other synonyms of sun lamp include sunlamp, sunray lamp.

sun lamp (noun)	sun-ray lamp (noun)
a mercury-vapor lamp used in medical or cosmetic treatments	a mercury-vapor lamp used in medical or cosmetic treatments