A Keyhole Neckline is a neckline style featuring a small cutout opening at the center of the neckline, designed to add subtle skin exposure and elegant decorative detail. Common elements include teardrop or circular cutouts, button or tie closures, high-neck or round-neck variations, and frequent use in dresses, blouses, and formal tops. The overall style emphasizes refinement, softness, and understated sensuality, creating an elegant and feminine fashion look.