A grille is a framework of bars or wires arranged in a crisscross pattern, usually placed over an opening. You see grilles covering floor vents in your house, protecting the speakers in your stereo, or forming the front of a car where air flows into the engine. The pattern of bars lets air, sound, or light pass through while keeping larger objects out.

Grilles serve both practical and decorative purposes. A metal grille over a window can prevent break-ins while still letting in fresh air. The ornate grilles on historic buildings often feature beautiful metalwork that makes them architectural features worth admiring. Modern car designers spend significant time on grille design because it affects both how the car looks and how efficiently it cools the engine.

You might also see grilles protecting expensive or delicate equipment. A fan has a grille covering its blades to keep fingers safe. A radiator grille allows heat to escape while protecting the hot metal inside.

Sometimes grille is spelled grill, which can cause confusion with the cooking appliance. When you're talking about that crisscross protective covering, grille with an “e” is the preferred spelling. When you're talking about cooking burgers outdoors, that's a grill without the “e.”