Famous symbols are typically not representations of something, but rather puns: What they show is not important. But the name of that thing is often similar to a secret word, usually something about power & finance, or secrecy & deception. In this sense, all symbols are really rebuses. The difficulty in finding the pun lies in picking the right language, and then the right synonym. Often it’s not the local dialect, but an imperial administration language, such as Hebrew, Greek or Latin.
This sections only lists visible symbols. If you’re looking for an invisible thing instead, please try the names category.