hind end vs posterior

hind end and posterior both are nouns.

Word	Noun	Adjective	Verb	Adverb
hind end	Yes	No	No	No
posterior	Yes	Yes	No	No

As nouns, hind end and posterior are synonyms defined as:

hind end and posterior: the fleshy part of the human body that you sit on

hind end (noun)	posterior (noun)
the fleshy part of the human body that you sit on	the fleshy part of the human body that you sit on
	a tooth situated at the back of the mouth

hind end (adjective)	posterior (adjective)
	located at or near or behind a part or near the end of a structure
	coming at a subsequent time or stage