When searching for antonyms for the word "most expired", we must first understand the meaning of the word. "Expired" refers to something that has reached its expiration date or has become outdated. Therefore, antonyms for "most expired" would include "fresh," "new," "recent," and "current." These words indicate the opposite of something that is old or outdated, and instead suggest something that is modern and up-to-date. Additionally, words like "valid," "usable," and "effective" can also serve as antonyms for "most expired." These words indicate that something is still functional and relevant, whereas something that is "most expired" is not.