"a knuckle sandwich" in Chinese (Traditional)
一記老拳（幽默表達）
Definition
幽默或玩笑地表示「打嘴巴」或「打臉的一拳」的說法。
Usage Notes (Chinese (Traditional))
這是一種非常口語和幽默的說法，常見於朋友之間的玩笑。不是認真的威脅，而是開玩笑或調侃。常出現在漫畫、電影或朋友間打趣時。
Examples
If you keep teasing me, you'll get a knuckle sandwich!
你再逗我，小心**一記老拳**！
Tom laughed when his friend threatened him with a knuckle sandwich.
湯姆笑了，當朋友拿**一記老拳**威脅他時。
Nobody actually wants a knuckle sandwich.
其實沒有人真的想要**一記老拳**。
He was joking when he offered me a knuckle sandwich for taking the last cookie.
我拿了最後一塊餅乾，他開玩笑說要給我**一記老拳**。
She threatened him with a knuckle sandwich, but everyone knew she was kidding.
她威脅說要給他**一記老拳**，但大家都知道她在開玩笑。
Mess with him again and you might just get a knuckle sandwich!
再惹他，可能會喫到**一記老拳**！