"Un-newest" is a term used to describe something that is not the latest or most recent. There are several synonyms for this word that can be used to describe the same thing. Some of these include "older," "outdated," "obsolete," "antiquated," "archaic," and "vintage." These words can be used in different contexts depending on the age of the item or idea being referred to. For example, an older car may be considered vintage or classic, while an outdated idea may be considered archaic or obsolete. Overall, using synonyms for "un-newest" can add variety and specificity to your writing.