muscle fibre vs muscle fiber

muscle fibre and muscle fiber both are nouns.

Word	Noun	Adjective	Verb	Adverb
muscle fibre	Yes	No	No	No
muscle fiber	Yes	No	No	No

As nouns, muscle fibre and muscle fiber are synonyms defined as:

muscle fibre and muscle fiber: an elongated contractile cell that forms the muscles of the body

Other synonyms of muscle fibre include muscle cell.

muscle fibre (noun)	muscle fiber (noun)
an elongated contractile cell that forms the muscles of the body	an elongated contractile cell that forms the muscles of the body