glass fiber vs American spelling

glass fiber and American spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
glass fiber	Yes	No	No	No
American spelling	Yes	No	No	No

glass fiber (noun)	American spelling (noun)
a very thin fiber made of glass that functions as a waveguide for light; used in bundles to transmit images	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')