n. then v. Based on
the model of the noun "hard on", a hate on is an active hatred for someone or something that causes a visible physical reaction in a similar fashion that an erection would be a tell-tale sign of affection. Despite its origin, it is rarely used in a sexual context. It is male juvenile slang
in the sense that it links, even indirectly, an emotion (hatred, jealousy, envy) to the male teenage obsession with
the penis.