RevokePrivileges MySQL
REVOKE ALL ON dbname.* FROM 'username'@'localhost';
Splendid Sheep
REVOKE ALL ON dbname.* FROM 'username'@'localhost';REVOKE ALL PRIVILEGES ON database_name.* FROM 'username'@'host';
OR
DROP USER 'username'@'host';DROP USER IF EXISTS 'user'@'127.0.0.1' ;