Ground meat and poultry thawed in the refrigerator can be used for one or two days after defrosting; red meat should remain usable for 3-5 days. Foods defrosted in the refrigerator can be refrozen without cooking, but it will decrease the shelf life next time it is defrosted.
If you’re in a hurry, resist the temptation to thaw your meat in a bowl of warm water. Meat that is left at above 40F is in the “danger zone” for the proliferation of harmful bacteria. Speedier defrosting can be achieved by submersion in cold water. Make sure the meat is in a sealed, leak-proof container! Change the water ever 30 minutes or so. Small packages of meat or poultry – about a pound – may defrost in an hour or less. A 3- to 4-pound package may take 2 to 3 hours.
For sources and more information on safe defrosting, see The Big Thaw