What does "tail end" mean?

The hindmost part of anything (a person, animal, or object), the rear end; the butt, buttocks; hindquarters, rump.

What is a synonym for "tail end"?

Common synonyms include: afterpart, arse, ass, back, back door, back seat.

noun

noun ·Uncommon ·Advanced level

Noun

1
The hindmost part of anything (a person, animal, or object), the rear end; the butt, buttocks; hindquarters, rump.
2
the fleshy part of the human body that you sit on wordnet
3
The last part of a period of time, event, or situation; the concluding or final part. figuratively
"At the tail end of summer."
4
any projection that resembles the tail of an animal wordnet
5
the time of the last part of something wordnet

"The tail end of a conversation."

From Middle English taylende; equivalent to tail + end.