dimple

A dimple is a small natural indentation in a surface or body. In humans, the term most often refers to a facial dimple—a shallow hollow that forms on the cheek or chin, especially when the person smiles. Facial dimples are usually present from birth and tend to run in families. They are thought to result from variations in the zygomaticus major muscle or from a partial muscular tether that creates a crease in the skin when facial muscles are engaged. The appearance of dimples can vary by age and expression; they may become less pronounced as soft tissues change with aging, though many people retain them into adulthood.

Beyond the skin, dimples describe intentional or natural depressions on round or irregular surfaces. In engineering and sports, dimples are small indentations designed to influence fluid flow. For example, the dimples on a golf ball create turbulence in the air near the surface, reducing drag and allowing the ball to fly farther. Dimples also appear on some heat exchanger surfaces and other engineered components to improve heat transfer or fluid dynamics by altering flow patterns.

Dimpled skin or surfaces are generally harmless and are considered a cosmetic trait in humans rather than a medical condition. They can be a distinctive physical feature and are sometimes culturally associated with attractiveness in different societies.