The term 'most timeworn' implies something that is old, weathered or worn out due to the passage of time. Its antonyms would be words that describe objects or places that are new, shiny, and fresh. These could include terms such as recent, modern, contemporary, state-of-the-art, and innovative. The opposite of timeworn could also be described by words like pristine, immaculate, unblemished, and spotless. These words denote things that are new or untouched by time, which could be used to describe a new building, a sparkling car, or a freshly paved road. Therefore, when trying to convey the opposite of something timeworn, these are some of the words that can be used.