A lozenge is a small, diamond-shaped object or design. You've probably seen lozenges on playing cards: the red diamond suit is made up of lozenges. Medieval knights often displayed lozenges on their shields and banners, and you'll still see this geometric pattern in stained glass windows, tile floors, and quilts.

The word also describes a type of medicine you dissolve slowly in your mouth, like a cough drop. These medicinal lozenges got their name because they were originally pressed into that diamond shape. When your throat hurts, you might suck on a throat lozenge that releases medicine gradually as it dissolves. The shape doesn't matter much anymore: modern cough drops come in circles, ovals, and other shapes, but we still call them lozenges.

In mathematics and geometry, a lozenge is technically a rhombus: a four-sided shape where all sides are equal in length but the angles aren't right angles, creating that characteristic slanted diamond appearance.