Oh, now, here’s a word for something you get up to. And the word gets up, too: look at those three dots in a row, like high spirits, high hands, perhaps lighters held aloft or, well, who knows what – better duck. And they’re bookended by the h on one side and, on the other, what used to be an h but has gotten a bit of a kicking so that the lower part (n) has separated, and not without damage to the upright, which is splintered (k). Clearly damage accelerates quicker when aided by a lot of liquor.
Oh, but these are merely youthful high spirits! Well, high jinxes, too. Not etymologically, though – jinx comes from the name of a bird (jynx, better known as wryneck) said to be used in witchcraft (perhaps to curse a person with torticollis, given its other name), whereas the jinks in hijinks is a plural noun referring to a drinking game (yep), named with a noun referring to a tricky, elusive turn (as in rugby), which in turn is a conversion from the verb jink, which refers to the same action, the sort of move you would make with a 250-pound tackle aiming for you – or perhaps a machine gun emplacement behind you. It’s also somewhat like the moves your fingers make when typing hijinks. (The sudden change may also bring to mind hikinuki, a sudden change in kabuki – I mean a sudden change of costume!) And the verb jink? Just made up because it sounded right for the move. The Oxford English Dictionary calls it onomatopoeia, but the move doesn’t really go “jink, jink, jink”; it’s more in the way of sound symbolism: there’s that jumpy j and the quick-as-a-wink ink. As to the hi, it’s not a greeting (though the greeting “Hi, Jinx!” might lead to some hijinks), it’s high shortened and attached. The word was originally high jinks.
But, really, high jinks just does not party as hard as hijinks. Hijinks is a word for laughing off all manner of inebriated indiscretion and misjudgement, such as having some drinks on the links and using one of the lakes for a jakes, or going out for sushi, having too much sake and ending up dressed in hijiki (just don’t feast on the stuff; it’s slightly loaded with arsenic, dears).