The phrase "unattended to" is often used to describe something that has been neglected or ignored. There are many synonyms that can be used to convey this same meaning, including "unaddressed," "unresolved," "untended," "undealt with," "unacknowledged," and "unhandled." These words all suggest a lack of attention or care towards a certain issue, whether it be a problem that needs to be solved or a task that needs to be completed. It is important to recognize when something has been left "unattended to" so that it can be properly addressed and resolved.