A term used to refer to your GF or your wife, etc. Usually somebody who you may like, but really don't have much respect for. Also a term used out of habit by people usually living in lower income neighborhoods.
"Don't worry about it, I'll just get my old lady to make us something to eat."
"My old lady will take you to where you need to go."
"My old lady will never find out."
You never hear" I really love my old lady, she means the world to me"