Hijinks is the American one-word spelling of high jinks: noisy, playful trouble — fun that is a bit wild, a bit silly, and that can get you into a little bother. It is informal. You hear it in phrases like the usual hijinks or holiday hijinks, often with a smile, sometimes with a sigh. High jinks as two words is the older spelling and the one you are more likely to see in British writing; hijinks as one word is what many American writers use. The meaning is the same. It is not related to hijack, even though the letters sit close. Today it just means lively mischief, not a special game.

嬉鬧、胡鬧（high jinks 的美式連寫）