Be more careful; don't be so reckless. Steady on, kids—don't break anything in here. Steady on, there's no need to fight! Let's all just take a minute and calm down.
steady ˈon!(informal) be more careful about what you do or say; slow down: Steady on, you two, let’s not get angry! ♢ Steady on, you’ll break it!
See also: steady