When a person becomes drowsy from alcohol. Grey Goose is a type of Vodka.
Chamillionaire: If liquor makes him drowsy, he gonna say he got that grey goose disease
by wutzzzzzz June 16, 2008
the one motherly girl amongst the group who can still take care of friends (hold hair while friend throws up, walk friend to the restroom to piss, make drinks, carry/walk friend, etc.) while being drunk herself and not being bothered by it at all.
Girl: I really hope I don't get drunk and stupid at that party tonight.

Boy: Don't worry Diana is gonna be there. She usually enjoys playing the role of Mother Grey Goose when we're out at parties.
by the original MGG July 19, 2009