rear vs after part

rear and after part both are nouns.

Word	Noun	Adjective	Verb	Adverb
rear	Yes	Yes	Yes	No
after part	Yes	No	No	No

As nouns, after part is a hyponym of rear; that is, after part is a word with a more specific, narrower meaning than rear:

Other hyponyms of rear include poop, quarter, stern, tail, empennage, tail, tail assembly.

rear (noun)	after part (noun)
the side that goes last or is not normally seen	the rear part of a ship
the fleshy part of the human body that you sit on
the back of a military formation or procession
the side of an object that is opposite its front
the part of something that is furthest from the normal viewer

rear (adjective)	after part (adjective)
located in or toward the back or rear

rear (verb)	after part (verb)
construct, build, or erect
stand up on the hind legs, of quadrupeds
cause to rise up
look after a child until it is an adult
rise up