phosphor vs synthetic substance

phosphor and synthetic substance both are nouns.

Word	Noun	Adjective	Verb	Adverb
phosphor	Yes	No	No	No
synthetic substance	Yes	No	No	No

As nouns, synthetic substance is a hypernym of phosphor; that is, synthetic substance is a word with a broader meaning than phosphor:

phosphor: a synthetic substance that is fluorescent or phosphorescent; used to coat the screens of cathode ray tubes
synthetic substance: a compound made artificially by chemical reactions

Other hypernyms of phosphor include synthetic.

phosphor (noun)	synthetic substance (noun)
a synthetic substance that is fluorescent or phosphorescent; used to coat the screens of cathode ray tubes	a compound made artificially by chemical reactions