nucha vs back end

nucha and back end both are nouns.

Word	Noun	Adjective	Verb	Adverb
nucha	Yes	No	No	No
back end	Yes	No	No	No

As nouns, back end is a hypernym of nucha; that is, back end is a word with a broader meaning than nucha:

Other hypernyms of nucha include backside, rear.

nucha (noun)	back end (noun)
the back side of the neck	the side of an object that is opposite its front