Uninvited (adjective)

Not having been asked or given permission to come to a particular event or place.

Origin:

The word "uninvited" is derived from the prefix "un-" meaning "not" or "reverse of" and "invited" which means having been asked or given permission to come to a particular event or place.

Examples:

1. He showed up at the party uninvited.
2. She felt uninvited to the meeting.
3. The guest arrived uninvited to the wedding.
4. I would feel uninvited showing up to the meeting without an invitation.
5. The protesters came uninvited to the rally.