tail end vs sex activity

tail end and sex activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
tail end	Yes	No	No	No
sex activity	Yes	No	No	No

tail end (noun)	sex activity (noun)
the fleshy part of the human body that you sit on	activities associated with sexual intercourse
any projection that resembles the tail of an animal
the time of the last part of something