There are many antonyms for the phrase "wert subsequent to," which means "following after" or "occurring later than." Some of these antonyms could include "former," "earlier," "prior to," or "preceding." Essentially, any word that suggests something coming before something else could be considered an antonym for "wert subsequent to." For example, if you were discussing historical events, you might say that the American Revolution was subsequent to the French and Indian War, meaning it came after. The antonym would be to say the French and Indian War was prior to, or preceding, the American Revolution.