What is Ouster?

Legal Definition
Torts. An ouster is the actual turning out, or keeping excluded, the party entitlod to possession of any real property corporeal.

2. An ouster can properly be only from real property corporeal, and cannot be committed of anything movable; 1 Car. & P. 123; S. C. 11 Eng. Com. Law R. 339; 2 Bouv. 1 Inst. n. 2348; 1 Chit. Pr. 148, note r; nor is a mere temporary trespass considered as an Guster. Any continuing act of exclusion from the enjoyment, constitutes an ouster, even by one tenant in common of his co-tenant. Co. Litt. 199 b, 200 a. Vide 3 Bl; Com. 167; Arch. Civ. Pl. 6, 14; 1 Chit. Pr. 374, where the remedies for an ouster are pointed out. Vide Judgment of Respondent Ouster.
-- Bouviers Law Dictionary
Legal Definition
In practice. A putting out; dispossession; amotion of possession. A species of injuries to things real, by which the wrong-doer gains actual occupation of the rland, and compels the rightful owner to seek his legal remedy in order to gain possession. 2 Crabb, Real Prop. p. 1063, ยง 2454a. See Ewing v. Burnet, 11 Pet. 52, 9 In Ed. 624; Winterburn v. Chambers, 91 Cal. 170, 27 Pac. 658; McMullin v. Wooley, 2 Lans. (N. Y.) 396; Mason v. Kellogg, 38 Mich. 148. See Actual ouster.
-- Black's Law Dictionary
Legal Definition
The wrongful dispossession or exclusion of a party, who is entitled to possession, from real property. See 116 Am. St. Rep. 570, note.
-- Ballentine's Law Dictionary