trespasser

Concise Oxford English Dictionary © 2008 Oxford University Press:
trespass/ˈtrespəs/

▶verb

• 1 enter someone's land or property without permission.

• 2 (trespass on) make unfair claims on or take advantage of (something).

• 3 (trespass against) archaic or literary commit an offence against (a person or a set of rules).

▶noun

• 1 Law entry to a person's land or property without their permission.

• 2 archaic or literary a sin or offence.

– derivatives
trespasser noun.

– origin ME: from OFr. trespasser ‘pass over, trespass’, trespas ‘passing across’, from med. L. transpassare (see trans-, pass1).