Iconoclastic describes ideas, opinions, writing, art, or people that attack established beliefs and customs. If a book is iconoclastic, it does not politely sit beside the usual view; it goes after it. A film, a joke, a scientific paper, even a way of dressing can be called iconoclastic when it is aimed at what a group treats as fixed. It does not have to be loud or rude — the point is that it will not leave the old picture standing. Like iconoclast, it is a grown-up word: reviews, essays, serious talk. People sometimes water it down to mean ‘edgy’ or ‘a bit different’. That is weaker than the real charge. Iconoclastic is not only new; it is against what is already established.