Other forms: bulbs
A bulb is the glass ball that makes light in a lamp. Change the bulb, a dead bulb, a bright bulb.
The old filament kind turned most of its power into heat and only a small part into light, which is why they were banned. In gardening a bulb is an underground storage organ — a tulip bulb — and that is the older sense. Note that the Latin bulbus means an onion.
1nounbulbThe glass ball that makes light in a lamp.
“The bulb in the kitchen has gone, so we need a new one.”
2nounundergroundAn underground storage organ of a plant.
“In autumn we planted daffodil bulbs along the garden path.”
bulb is a lamp part, or a plant part.
Also accepted in games: light bulb
Latin bulbus means a bulb or onion, from Greek bolbos. The lamp sense comes from the shape.
Middle English
bulb
Latin
bulbus
English, today
bulb
From Latin bulbus. Middle English bulb, bolbe, from Latin bulbus (“bulb, onion”), from Ancient Greek βολβός (“plant with round swelling on underground stem”).
Etymology from Wiktionary, CC BY-SA