1. To tease, mock, or ridicule someone. Primarily heard in Australia, New Zealand. Ah, don't take everything so personally, I'm only slinging off at you! It took me a while to get used to the way Sarah's family slings off at each other off all the time.

2. To criticise or upbraid someone in a harsh, insulting, and abusive manner. Primarily heard in Australia, New Zealand. I wish the boss would offer some constructive criticism instead of just slinging off at us when something goes wrong. I'm so glad the neighbours moved. Every night, the wife slung off at her husband, and it was incredibly irritating to listen to.