motoneuron vs motor nerve fiber

motoneuron and motor nerve fiber both are nouns.

Word	Noun	Adjective	Verb	Adverb
motoneuron	Yes	No	No	No
motor nerve fiber	Yes	No	No	No

As nouns, motoneuron and motor nerve fiber are synonyms defined as:

motoneuron and motor nerve fiber: a neuron conducting impulses outwards from the brain or spinal cord

Other synonyms of motoneuron include efferent neuron, motor neuron.

motoneuron (noun)	motor nerve fiber (noun)
a neuron conducting impulses outwards from the brain or spinal cord	a neuron conducting impulses outwards from the brain or spinal cord