neuropil vs nervous tissue

neuropil and nervous tissue both are nouns.

Word	Noun	Adjective	Verb	Adverb
neuropil	Yes	No	No	No
nervous tissue	Yes	No	No	No

As nouns, nervous tissue is a hypernym of neuropil; that is, nervous tissue is a word with a broader meaning than neuropil:

neuropil: the complex network of unmyelinated axones, dendrites, and glial branches that form the bulk of the central nervous system's grey matter and in which nerve cell bodies are embedded
nervous tissue: tissue composed of neurons

Other hypernyms of neuropil include nerve tissue.

neuropil (noun)	nervous tissue (noun)
the complex network of unmyelinated axones, dendrites, and glial branches that form the bulk of the central nervous system's grey matter and in which nerve cell bodies are embedded	tissue composed of neurons