Final answer:
An ordinary life estate is one in which the duration is measured by the lifetime of the life tenant, meaning it lasts until the life tenant dies.
Step-by-step explanation:
An ordinary life estate is one in which the duration is measured by the lifetime of the life tenant. This means that the life estate lasts until the life tenant dies. Once the life tenant passes away, the estate typically reverts back to the original owner or goes to a remainderman.