As "symbolled" is a verb, antonyms would also be verbs indicating the opposite action. Some antonyms could be "erase," "obliterate," "remove," "undesignate," or "unravel." These words mean to eliminate or eradicate symbols or remove their significance. For example, you could erase a symbol from a whiteboard or remove a symbol from a document. Alternatively, you could also use a word that indicates the lack of symbolism, such as "unmarked" or "unadorned," meaning something without any symbolic meaning or adornment. Ultimately, using the right antonym for "symbolled" would depend on the context in which it is used.