刀疤 (dāo bā) literally means 'knife scar' — a permanent mark left on the skin after a cut or wound caused by a sharp object like a knife. The first character, 刀 (dāo), means 'knife' or 'blade', and the second, 疤 (bā), means 'scar' or 'scar tissue'. Together, they specifically refer to scars resulting from lacerations rather than burns, surgery, or acne. While not exclusively medical terminology, it’s commonly used in everyday speech when describing visible, linear scars on the body.

This word carries a neutral-to-slightly informal register and is often used in personal narratives, descriptions of appearance, or casual health-related conversations. It does not imply severity — a small kitchen cut can leave a 刀疤, as can a deeper injury. Unlike generic terms like 伤疤 (shāng bā, 'injury scar'), 刀疤 emphasizes the cause: a sharp, cutting instrument. It’s rarely used metaphorically and almost always refers to physical scarring on human skin.