tail end vs derriere

tail end and derriere both are nouns.

Word	Noun	Adjective	Verb	Adverb
tail end	Yes	No	No	No
derriere	Yes	No	No	No

As nouns, tail end and derriere are synonyms defined as:

tail end and derriere: the fleshy part of the human body that you sit on

tail end (noun)	derriere (noun)
the fleshy part of the human body that you sit on	the fleshy part of the human body that you sit on
any projection that resembles the tail of an animal
the time of the last part of something