It's a term used by Uffie in her song, Pop the Glock. It means one can drive with his gang/or people. Usually, the people are just known as a car not to be messed with...maybe they are part of a gang or they have drugs or they will just kick someone's butt in general.
"Me and He are crusalicious, better watch out our clan gets vicious."
You're not going out with him/her, but you do like them, and they like you too. Basically you act like you're in a relationship and get jealous when they talk to the opposite gender.
(In Kelly's head): Danny is so cute!! Aww we would look so cute together!!
Danny: Hey Kelly.
Kelly: OMGOMG ARHAERIHgshroihERK HI DANNY!
Danny: You cute. I'ma talk to Cindy.
Danny: Hey cindy, you hot.
Kelly: WTFFFF WE'RE IN A CRUSHATIONSHIP!! YOU BROKE MY HEART!
Danny: *just ignores* So yeah Cindy, Prom 201_?