Final answer:
An epidural hematoma is defined as bleeding between the dura mater and brain, which occurs when a blood vessel ruptures.
Step-by-step explanation:
An epidural hematoma is most accurately defined as bleeding between the dura mater and brain. It occurs when a blood vessel, usually an artery, ruptures and causes bleeding in the area between the dura mater (the outermost protective membrane of the brain) and the brain itself. This accumulation of blood puts pressure on the brain and can lead to serious consequences if not treated promptly.