squat·ter / ˈskwätər/ • n. a person who unlawfully occupies an uninhabited building or unused land. ∎ hist. a settler with no legal title to the land occupied, typically one on land not yet allocated by a government.
An individual who settles on the land of another person without any legal authority to do so, or without acquiring a legal title.
In the past, the term squatter specifically applied to an individual who settled on public land. Currently it is used interchangeably with intruder and trespasser.