neurolemma vs sheath

neurolemma and sheath both are nouns.

Word	Noun	Adjective	Verb	Adverb
neurolemma	Yes	No	No	No
sheath	Yes	No	No	No

As nouns, sheath is a hypernym of neurolemma; that is, sheath is a word with a broader meaning than neurolemma:

neurolemma: thin membranous sheath around a nerve fiber
sheath: an enveloping structure or covering enclosing an animal or plant organ or part

Other hypernyms of neurolemma include case.

neurolemma (noun)	sheath (noun)
thin membranous sheath around a nerve fiber	a protective covering (as for a knife or sword)
	a dress suitable for formal occasions
	an enveloping structure or covering enclosing an animal or plant organ or part