fibreglass vs fiberglass

fibreglass and fiberglass both are nouns.

Word	Noun	Adjective	Verb	Adverb
fibreglass	Yes	No	No	No
fiberglass	Yes	No	No	No

As nouns, fibreglass and fiberglass are synonyms defined as:

fibreglass and fiberglass: a covering material made of glass fibers in resins

fibreglass (noun)	fiberglass (noun)
a covering material made of glass fibers in resins	a covering material made of glass fibers in resins