uninvited
adj. B2 Upper Intermediate US //ˌənɪnˈvaɪtɪd// UK //ˌʌnɪnvˈaɪtɪd// un·in·vit·ed
adj. not asked to come or not allowed to enter. You use this to describe someone who arrives without permission.
adj. not requested or permitted to enter or attend. Often used to describe guests or visitors who arrive without an invitation.
He arrived at the party uninvited.
The security guard asked the uninvited guests to leave the building immediately.
The presence of uninvited guests at the private ceremony caused a significant disruption, leading to a formal complaint from the event organizers.