intruder
//ɪnˈtruːdər//
Noun
intruderSingular
intrudersPlural
1
A person who enters a place, situation, or sphere of activity without permission or welcome.
The security camera captured an intruder entering the building.
2
A person or thing that intrudes on another's privacy, property, or domain.
The security camera captured an intruder entering the backyard.