What is opp in slang?

"Opp" is slang for "opposition" or "opponent." It is commonly used in urban communities to refer to someone who is a rival, enemy, or someone who is not on your side. It can also be used to describe someone who is going against you or causing problems for you. Additionally, "opp" can be used as a verb to mean to go against or compete with someone. It is often used in rap lyrics and street culture.