Ejectment is an English common law Form Of Action for the recovery of Realty, Real Estate specifically. If the plaintiff prevails at trial, the court will award him his remedy under his action of ejectment, which is a Writ Of Possession for recovery of possession of the real estate in question.
Ejectment is premised on a legal fiction known as "casual ejector", designed to circumvent some of the limitations of the old English court system. A legal action in ejectment creates a fictional stipulation of fact which allows the case to be tried within the jurisdiction of the English Court of King's Bench rather than the English Court of Common Pleas. A disadvantage of Common Pleas at first was that precedents made the selection of diverse Real Actions too difficult, and therefore the ejectment, with its fiction, was eventually welcomed as a means of simplifying and consolidating many real actions.
In the United States it is used as an alternate term for eviction.