Meaning & use
bulb
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Meanings
nouncountable
A glass or similar device that gives light when electricity passes through it, fitted into a lamp or fixture.
Grammar: Countable and often in the compound light bulb: change the bulb.
Patterns
- change a bulb
- a bulb in something
The bulb in the hallway burned out last night.
He screwed a new bulb into the lamp.
Energy-saving bulbs last much longer than old ones.
nouncountablebiology
A round underground part of some plants, such as tulips and onions, from which the roots and shoots grow.
Grammar: Countable: plant the bulbs in autumn.
Patterns
- plant bulbs
- a bulb of something
She planted tulip bulbs along the front walk in October.
An onion is the swollen bulb of the plant.
The daffodil bulbs sprouted after the first warm week.
nouncountabletechnical
A round, swollen part at the end of something, such as the end of a thermometer or a syringe-like tool.
Grammar: Countable and usually followed by of or used with another noun: a rubber bulb.
Patterns
- the bulb of something
Mercury rose from the glass bulb of the thermometer.
He squeezed the rubber bulb to draw up the oil.
The pipette has a soft bulb at the top.
Word forms
| plural | bulbs |
|---|
Common combinations
- light bulb
- A light bulb flickered above the stairs.
- change a bulb
- It took two minutes to change the bulb.
- plant bulbs
- We plant bulbs in autumn so they flower in spring.
- a bulb burns out
- A bulb burned out in the middle of dinner.
- tulip bulb
- A single tulip bulb can produce a new flower each year.
- energy-saving bulb
- An energy-saving bulb cut our electricity use.
Synonyms and how they differ
- lamp
- Lamp usually means the whole light fitting, whereas a bulb is only the part that produces the light.
- corm
- A corm is a solid swollen stem, like the crocus, and a bulb is made of layers, like an onion.
- tuber
- A tuber, such as a potato, is a swollen underground stem used for storage, not a layered bulb.
Word family
- bulbous adjective
- round and swollen, like a bulb
- bulbil noun
- a small bulb that grows on a plant and can develop into a new plant
- bulblet noun
- a small bulb that grows from a larger one
Commonly confused: bulb or lamp?
bulb vs lamp
A lamp is the whole device, with its base and shade, while the bulb is the replaceable part inside that makes the light.
Practice
In the sentence 'We planted tulip bulbs in the fall,' what does bulb mean?
Choose one answer.
Tulip bulbs are the underground storage parts from which the flowers grow. The glass bulb in a lamp is a different sense.
Make it your own
Write a sentence using “bulb”, then check it and compare it with the examples above.