bulb

Universal Words noun 1 (also light bulb) the glass part that fits into an electric lamp, etc. to give light when it is switched on: a 60-watt bulb * a room lit by bare bulbs (= with no decorative cover) 2 the round underground part of some plants, shaped like an onion, that grows into a new plant every year: daffodil bulbs * the bulb fields of Holland 3 an object shaped like a bulb, for example the end of a THERMOMETER