These words refer to an unwelcome advance, usually upon someone else’s territory or privacy. Encroach emphasizes the slowness or subtlety of an advance that may at first have proceeded without a countering complaint only to be recognized finally as a threat: powers of the executive branch that have gradually encroached on the rights of the other branches; a mother-in-law whose attentions are not meant to encroach on the privacy of the newly married couple; urban sprawl that encroaches on unspoilt countryside.

Intrude is more often limited to overstepping of personal privacy than to territorial expansion. It suggests a situation in which a person or group has deliberately withdrawn in order to escape interruption ?but without success: parents who intrude on the secrecies of childhood. Unlike encroach , however, intrude may more often be unintentional or sudden: embarrassed at finding that he had intruded on the young lovers. It can sometimes be used more generally, but the note of a personal situation is still retained: newspapers that attempt to intrude on the decision-making process.

Invade and violate are much harsher terms; they would never suggest unintentional acts, like intrude , nor gradual acts, like encroach . They may, in fact, suggest savagery and violence. Invade most readily brings to mind a military attack by one nation on another: the day Hitler invaded Poland. In other uses this context of military conquest is usually present as a negative connotation: forests invaded by timber speculators. Violate has both a sexual and a legal context: a woman violated by her attacker; a court ruling that basic constitutional rights had been violated . In more general uses, it can express outage at unethical tactics: discrimination that violates the very ideals most citizens hold sacred.

Infringe and trespass are mainly restricted to a legal context and are consequently less intensely negative in tone than invade or violate . Infringe most appropriately refers to the violation of a principle or a legal right, while trespass most appropriately refers to the illegal use of or encroachment on someone else’s property: laws that infringe on free speech; infringing on a copyright; shooters who trespass on a farmer’s land. Infringe , thus, compares with intrude , but does not have the personal tone of the latter. Trespass , similarly, compares with invade , but need not imply a concerted attack. Both infringe and trespass , of course, have wider applications, although they carry with them connotations from these most specific uses.