A very skinny, flat chested female with elongated nipples who appears to be a nerdy and non-sociable slag on the outside but a real screamer in the sack
"Had a boring lunch with Michelle the other day but she became a real McSnatch when I got her home to bed"
A nickname for someone who easily gets annoyed; someone who has a big forehead. You can call someone who tells people everything and is always loud and obnoxious a McSnitcherson.