fibre bundle vs fiber bundle

fibre bundle and fiber bundle both are nouns.

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

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

fibre bundle and fiber bundle: a bundle of fibers (especially nerve fibers)

Other synonyms of fibre bundle include fascicle, fasciculus.

fibre bundle (noun)	fiber bundle (noun)
a bundle of fibers (especially nerve fibers)	a bundle of fibers (especially nerve fibers)