A bar held up in the air, and one person running at it. Everyone takes the same height; then the bar goes up again. You stay in as long as you can get over it, and the moment you cannot, you are out.
The noun high jumper is formed from high jump plus -er, the ending English uses for the person who does something.
high jumper 由 high jump 加上字尾 -er 組成，-er 指「做這件事的人」，所以字面就是「跳高的那個人」。
Wiktionary, entry 'high jumper': "From high jump + -er." (kaikki:3f6f69a190036ae4:1437818638)
From the picture
等著被處罰（英式口語，整組記）
這一組跟運動場上的跳高沒有明顯的關係，字面也猜不出意思。我們手上的資料沒有說明它是怎麼來的，所以這裡不編一個故事給它。把它當成一個要整組記住的英式口語說法就好。
noun · C1
If someone is for the high jump, or is in for the high jump, they are about to be punished for something they have done wrong — often told off severely, or made to leave their job. British English, informal.
要倒大楣了；準備被處分
noun · B1
The high jump is an athletics event in which each competitor runs up to a bar and jumps over it without knocking it down, and the bar is raised a little higher after every round.
跳高（田徑項目）
noun · B1
An athlete whose event is the high jump: the person who runs up to the bar and jumps over it.
跳高選手