CoD beef is when 2 or more people (most likely under 15) start trash talking eachother. It often ends up with them just blocking eachother, but sometimes it will go to the point where personal details are read out or sent by messages.
Roast beef is where the vaginal flaps look almost like a kebab droppedon the floor and picked back up shaped into a coochie this is nicknamed roast beef because peoples flaps can b brown