pathway vs peduncle

pathway and peduncle both are nouns.

Word	Noun	Adjective	Verb	Adverb
pathway	Yes	No	No	No
peduncle	Yes	No	No	No

As nouns, peduncle is a hyponym of pathway; that is, peduncle is a word with a more specific, narrower meaning than pathway:

pathway: a bundle of myelinated nerve fibers following a path through the brain
peduncle: a bundle of myelinated neurons joining different parts of the brain

Other hyponyms of pathway include optic radiation, radiatio optica, commissure, cerebral peduncle.

pathway (noun)	peduncle (noun)
a trodden path	a bundle of myelinated neurons joining different parts of the brain
a bundle of myelinated nerve fibers following a path through the brain	stalk bearing an inflorescence or solitary flower
	the thin process of tissue that attaches a polyp to the body