Ulcer (noun)

1. An open sore on an external or internal surface of the body, caused by a break in the skin or mucous membrane.
2. A painful area of breakdown in the skin or mucous membrane, typically with a raised edge and a yellowish or whitish center.

Origin:

Middle english: via old french from latin ulcus, ulcer- "a sore", from ulcēre "eat away".

Examples:

1. He had an ulcer on his leg that wouldn't heal.
2. The patient had a stomach ulcer and was experiencing severe pain.
3. It is important to keep the ulcer clean and covered to prevent infection.
4. The ulcer was caused by the patient's excessive use of non-steroidal anti-inflammatory drugs.
5. The doctor prescribed antibiotics to clear up the ulcer.