What is Private Property?

Legal Definition
Private property is a legal designation for the ownership of property by non-governmental legal entities. Private property is distinguishable from public property, which is owned by a state entity; and from collective (or cooperative) property, which is owned by a group of non-governmental entities. Private property is further distinguished from personal property, which refers to property for personal use and consumption. Private property is a legal concept defined and enforced by a country's political system.
-- Wikipedia
Legal Definition
Private Property: property owned by private parties - essentially anyone or anything other then the government. Private property may consist of real estate, buildings, objects, intellectual property (for example, copyrights or patents ).

This is distinguished from Public Property, which is owned by the state or government or municipality.
Legal Definition
The ownership of tangible and intangible goods by an individual who has exclusive rights over it. The transfer of a private property can take place only by the owner’s consent or through a sale or through its presentation as a gift.
Legal Definition
as protected from being taken for public uses, is such property as belongs absolutely to an individual, and of which he has the exclusive right of disposition; property of a specific, fixed and tangible nature, capable of being had in possession and transmitted to another, such as houses, lands, and chattels. Homochitto River Co.m'rs v. Withers, 29 Miss. 21, 64 Am. Dec. 126; Scranton v. Wheeler, 179 U. S. 141, 21 Sup. Ct. 48, 45 L. Ed. 126.
-- Black's Law Dictionary
Legal Definition
That which is one's own or which belongs or inhered exclusively in an individual person. See 179 U. S. 141, 45 L. Ed. 126, 21 Sup. Ct. Rep. 48. See, also, 29 Miss. 21, 64 Am. Dec. 126.
-- Ballentine's Law Dictionary