rear vs side

rear and side both are nouns.

Word	Noun	Adjective	Verb	Adverb
rear	Yes	Yes	Yes	No
side	Yes	Yes	Yes	No

As nouns, side is a hypernym of rear; that is, side is a word with a broader meaning than rear:

As nouns, side is a hypernym of rear; that is, side is a word with a broader meaning than rear:

Other hypernyms of rear include face.

rear (noun)	side (noun)
the side that goes last or is not normally seen	an extended outer surface of an object
the fleshy part of the human body that you sit on	either the left or right half of a body
the back of a military formation or procession	an aspect of something (as contrasted with some other implied aspect)
the side of an object that is opposite its front	an opinion that is held in opposition to another in an argument or dispute
the part of something that is furthest from the normal viewer	(sports) the spin given to a ball by striking it on one side or releasing it with a sharp twist
	a lengthwise dressed half of an animal's carcass used for food
	one of two or more contesting groups
	a family line of descent
	a surface forming part of the outside of an object
	a line segment forming part of the perimeter of a plane figure
	a place within a region identified relative to a center or reference location
	an elevated geological formation

rear (adjective)	side (adjective)
located in or toward the back or rear	located on a side

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