sheath vs lorica

sheath and lorica both are nouns.

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

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

sheath: an enveloping structure or covering enclosing an animal or plant organ or part
lorica: a hard protective sheath (as secreted by certain protoctists, for example)

Other hyponyms of sheath include theca, medullary sheath, myelin sheath, neurilemma, neurolemma, husk.

sheath (noun)	lorica (noun)
a protective covering (as for a knife or sword)	a hard protective sheath (as secreted by certain protoctists, for example)
a dress suitable for formal occasions
an enveloping structure or covering enclosing an animal or plant organ or part