Eroticism is the quality in a film, a painting, a dance, or a piece of writing that gives a feeling of sexual desire. You are not naming the pictures or books themselves (that would be erotica). You are naming the heat, the atmosphere, the way the work makes the body matter. A critic might praise the eroticism of a scene, or say a novel has little eroticism even when it talks about sex, because the feeling is not there. Though actually, people stretch it. A perfume advert can be said to have “eroticism” when it is only selling a mood. It is a slightly literary, slightly grown-up word — more at home in a review than in a chat on the bus.