Coinheritor is a word that means someone who shares inheritance or joint ownership. Some synonyms for coinheritor are co-heir, co-beneficiary, co-owner, co-shareholder, joint heir, and joint owner. These synonyms refer to someone who has an equal claim, right, or privilege over a certain inheritance or property. Co-heir and joint heir specifically point to the legal right passed down from a common ancestor. Co-beneficiary and co-shareholder denote someone who has a share in an asset or sum of money. Joint owner pertains to legal possession of a property or asset. All these synonyms encapsulate the notion of shared inheritance or property ownership.