Definition from Nolo’s Plain-English Law Dictionary
Ownership in which the owner does not have full right to the property, but could acquire full ownership if specific conditions are fulfilled -- the ownership is conditional on those conditions. For example, George is the alternate remainder beneficiary of his mother's life estate. Joan, his sister, is the primary remainder beneficiary. George only has conditional ownership of the estate because his ownership depends on Joan being dead when their mother dies. Also called contingent ownership.