What is what does this person is unavailable on messenger mean?

When someone is marked as unavailable on Messenger, it typically means that they have either logged out of the Messenger app or have turned off notifications for it. This can happen for a variety of reasons, such as being busy with other tasks, intentionally taking a break from social media, or simply not wanting to be disturbed at that moment.

It's important to respect someone's status as unavailable on Messenger and not try to contact them repeatedly if they have chosen not to be reached at that time. It's best to wait until they become available again or to reach out through a different means of communication if it's urgent.