What term refers to each owner having a right of possession to the entire property?

The term that describes each owner having a right of possession to the entire property is undivided interest. In a property ownership context, undivided interest means that despite multiple owners holding title to a property, each owner has the right to use and possess the entire property rather than a specific, divided portion of it. This concept is essential in understanding how co-ownership can function, allowing all owners to share equally in the benefits and responsibilities associated with the property.

In contrast, other ownership forms mentioned can have restrictions on usage or possession. For example, joint tenancy typically includes the right of survivorship and may imply some form of division in the co-ownership, as well as specific rules regarding the transfer of ownership upon death. An estate in severalty involves sole ownership by one individual, which does not apply here. Tenancy in common does allow for multiple owners, but it does not require equal shares or joint possession, meaning each owner could own different percentages of the property. Thus, undivided interest is the term that best fits the definition provided in the question.