neurofibril vs nerve fiber

neurofibril and nerve fiber both are nouns.

Word	Noun	Adjective	Verb	Adverb
neurofibril	Yes	No	No	No
nerve fiber	Yes	No	No	No

As nouns, nerve fiber is a hypernym of neurofibril; that is, nerve fiber is a word with a broader meaning than neurofibril:

neurofibril: Any of the long, thin, microscopic fibrils that run through the body of a neuron and extend into the axon and dendrites, giving the neuron support and shape.
nerve fiber: a threadlike extension of a nerve cell

Other hypernyms of neurofibril include nerve fibre.

neurofibril (noun)	nerve fiber (noun)
Any of the long, thin, microscopic fibrils that run through the body of a neuron and extend into the axon and dendrites, giving the neuron support and shape.	a threadlike extension of a nerve cell