Iconography is the way a people, a religion, or a political group shows ideas in pictures and images — the shared picture-language, not just one drawing. A halo over a saint, a party colour, a raised fist, a flag, a superhero’s costume: once you know the code, the image is doing work that words would also do. Art historians also use the word for the study of those codes (what a lily is doing in an old painting, what a certain animal means in a poster). The pieces are ‘image’ plus a bit that means ‘writing’ or ‘describing’. It is a specialist word: museums, film class, politics, not the dinner table. People sometimes stretch it to mean merely ‘the look of something’ (the iconography of a pop star). That looser use is common now, though actually the tighter sense is a shared set of images with meaning, not only a style.