the GNU version of the Collaborative International Dictionary of English
n. One who enters upon another's land, or violates his rights.
n. A transgressor of the moral law; an offender; a sinner.
The Century Dictionary and Cyclopedia
n. One who trespasses, or commits a trespass; one who invades another's property or rights, or who does a wrongful act.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. someone who intrudes on the privacy or property of another without permission
Word Usage
"If the trespasser is a child, you face a greater risk of liability, especially if the child was drawn to your property by an “attractive nuisance,” such as a pond or high tower or some fascinating machine."