Top definition
A general warning to the recipient their past, present or future conduct may result in injury to themselves. Said injury could be caused by the recipient or by others.

Popular in Australia.
Prisoner 1: I'm really enjoying being the prison snitch.

Prisoner 2: A frieny piece of advice. Watch your step or you might just do yourself a mischief
by Eug_2000 June 10, 2013
Get the mug
Get a Do yourself a mischief mug for your fish Larisa.