If your meat's not already sealed, put it in a leakproof bag, squeeze all the air out, and put it in a bowl of cold water – then put it into the fridge.
You should be especially careful when putting raw meat in the fridge.
Make sure it NEVER comes into contact with any ready-to-eat food. And also make sure that it can't drip onto other food.
Smaller cuts – like a steak or small bag of mince – will defrost in the fridge in just a few hours. A bigger cut can take up to 3 hours. Anything bigger than 2-3 kg should be defrosted in the fridge. Big joints might take a few days to defrost.
Once you've defrosted meat in a fridge it's recommended you cook it within 24 hours. Ideally, cook the meat immediately after it's defrosted.