Hijinks is informal and is most commonly used in the context of lighthearted situations. It’s also spelled high jinks.

Inside the Bears co-host @spiceadams brings his usual hijinks to #BearsCamp. WATCH: http://t.co/cRnziRYeV3 pic.twitter.com/ffUHyr297q

— Chicago Bears (@ChicagoBears) August 12, 2015

cant wait to see what delightful april fools pranks and silly hijinks all the ~☆♡brands♡☆~ have planned for us tomorrow!!!! going to be hard to fall asleep tonight!!!!!!!!!!

— raina douris (@RahRahRaina) April 1, 2019

Things I learned from sitcoms no. 2: If you overhear part of a conversation and act on the incomplete information, hijinks will ensue.

— Fighting a Migraine (@OminousHallways) December 15, 2020

Did you mean hijiki?