Hematoma

Definition of hematoma
National Cancer Institute

hematoma

(HEE-muh-TOH-muh)
A pool of mostly clotted blood that forms in an organ, tissue, or body space. A hematoma is usually caused by a broken blood vessel that was damaged by surgery or an injury. It can occur anywhere in the body, including the brain. Most hematomas are small and go away on their own, but some may need to be removed by surgery.

Source: NCI Dictionary of Cancer Terms