A word meaning "You only live in a mafia once." It was made up by some St.Agatha 7th grade girls who were pretending they were in a mafia when they were in math class.
G1: Hey lets go up to the math teacher and yell yolimo!
G2: KAY KAY!!!!!
*they go up to the math teacher with fingers around their eyes shouting YOLIMO YOLIMO YOLIMO!