You might have heard some of your friends using this term. As a person who uses this myself, it is very useful. You can use it to greet your friends. You can also use it as a way of saying "no".
You: "Hey miss gurl!"
Your friends: "Heyyyy"
or
You giving advice: "MISS GURL NO! HES CHEATINGON YOU! LEAVE HIM!"
Someone who is not good enough to be a friend. Someone who you who don’t really like or appreciate. Miss gurls DO NOT achieve bestie status. Often used as a slur when someone pisses you off.
“Miss gurl just cut me off in her Tahoe”
“I thought we were besties but your giving me heavy miss gurl vibes rn”