The phrase "most ago" is used to refer to something that happened in the distant past. However, there are several synonyms that can be used in its place. One of the most common is "long ago", which is often used to describe events or periods of time that occurred in the distant past. "Ancient", "antiquated" and "historic" are other synonyms that can be used to describe something that happened a long time ago. "Bygone" is another word that can be used to describe something that occurred in the distant past. Whatever word you choose, it should convey the sense of time passing, and the distance between the present and the occurrence of the event.