End Of A Line
noun
You already know that 最後 means "end" so the tail end is the end of a line.
さいこうび
This is a jukugo word that uses the on'yomi readings of the kanji. It isn't the same as 最後 though, so watch out for that! It uses the other on'yomi reading you learned with the kanji!
大人気のゲームを発売日に買うために開店前にお店に行ったけど、すでにお店の前から列の最後尾まで200mぐらいあった。
To buy a very popular game on the release day, I went to a store before they opened, but there was already a line from the store that was about 200-meters long to the end.
昨日通りかかったお店の列の最後尾にクリステンがいたよ。仕事をサボって何買いに行ってたんだろう？
I saw Kristen at the end of a line for a shop I passed by yesterday. I wonder what she was playing hooky from work to get.
行列の最後尾はこちらです。
The end of the line is this way.