Trespass upon is a phrase which means to intrude or violate someone or something's property, space or rights. Some synonyms for this phrase include encroach, infringe, intrude, penetrate, trespass, violate, or intrude upon. These words all denote an uninvited presence or action that is bound to intrude on someone's space or property. When someone trespasses upon another's property or space, it is always considered a violation of privacy or personal space. In addition, the phrase trespass upon can be used in a legal sense to refer to someone who enters a property without permission or authorization. Therefore, it is important to use these synonyms in the right context and with caution.