Which type of property ownership refers to ownership by one person or entity?

The correct answer is ownership in severalty. This term specifically indicates that a single individual or entity holds the title and has exclusive rights to the property. Ownership in severalty is characterized by the absence of any co-owners in the property, meaning that the owner can make decisions about the property without needing to consult anyone else. This autonomy is a fundamental aspect of ownership in severalty, allowing the sole owner to manage, sell, or otherwise deal with the property as they see fit.

In contrast, other forms of ownership, like joint tenancy and tenancy in common, involve multiple parties sharing ownership rights, which can complicate decision-making and management of the property. Co-ownership encompasses those shared ownership arrangements, further differentiating it from ownership in severalty. Therefore, ownership in severalty is exclusively defined by individual ownership without the presence of other co-owners.