rear vs tail

rear and tail both are nouns.

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

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

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

As nouns, rear and tail are synonyms defined as:

rear (noun)	tail (noun)
the side that goes last or is not normally seen	the posterior part of the body of a vertebrate especially when elongated and extending beyond the trunk or main part of the body
the fleshy part of the human body that you sit on	the rear part of a ship
the back of a military formation or procession	the rear part of an aircraft
the side of an object that is opposite its front	(usually plural) the reverse side of a coin that does not bear the representation of a person's head
the part of something that is furthest from the normal viewer	the fleshy part of the human body that you sit on
	a spy employed to follow someone and report their movements
	any projection that resembles the tail of an animal
	the time of the last part of something

rear (adjective)	tail (adjective)
located in or toward the back or rear

rear (verb)	tail (verb)
construct, build, or erect	remove or shorten the tail of an animal
stand up on the hind legs, of quadrupeds	remove the stalk of fruits or berries
cause to rise up	go after with the intent to catch
look after a child until it is an adult
rise up