trespasser

noun

tres·pass·er

ˈtres-ˌpa-sər, -pə-

: one who trespasses

especially : one who enters or remains on the real property of another wrongfully or without the owner's or possessor's authority or consent compare invitee, licensee

Note: The general rule is that the owner or possessor of real property has the duty merely to refrain from willfully, wantonly, or recklessly injuring a trespasser whose presence is known. This rule is usually applied to licensees as well, although a licensee is usually owed a higher degree of care when an entrance fee is charged or when active operations (as of machinery) are taking place on the property.