Definition of hairline

The term "hairline" originates from the Old English words "hār" meaning "hair" and "līn" meaning "line" or "edge". In the 14th century, the word "hairline" referred to the edge or boundary of the hair on the forehead, scalp, or body. Over time, the term took on a more specific meaning, referring to the edge or margin of a person's forehead hair, particularly at the forehead's outermost point. In the late 18th century, the word's meaning expanded to include the superficial layer of hair on the forehead, often used to describe the shape or curvature of an individual's hair as it transitions from the forehead to the scalp. Today, the term "hairline" is commonly used in both medical and cosmetic contexts to describe the appearance and shape of a person's hairline, particularly in reference to hair loss or male pattern baldness.