An “Opp” or the “opposition” is slang for rival gang member or enemy, you can usually spot an opp in a group of four some common opp names are Alexis,Ben,Micheal, and Joseph. Opps call other people opps in fear of being discovered as an opp themselves, Raul on the other isn’t an Opp
This term is a slang form of the 3 commonly used synonyms listed above. (note none of these words have the same meaning except they are very synonymous, making the use of the word opp, an acceptable replacement for all 3 in slang terms).
Aye g, there go that opp boy we saw on this block yesterday.