1.Sl. to help someone escape from prison. (Bust is a non-standard form of burst meaning 'break' here.) Lefty did not manage to bust Max out of prison.Lefty wanted to bust out some of his friends.
2. Sl to expel or force someone to withdraw from school. (Bust is a nonstandard form of burst meaning 'break' here.) The clean finally busted Bill out of school.The clean busted out the students with very low grades.
in. to break out of some place, especially a prison. (Bust is a nonstandard form of burst meaning “break” here.) Somehow the gangsters busted out of prison and left the country.