Illustration of bulb
- 1 hyacinth
- 2 onion
- 3 tulip
- 4 lily
plural bulbs
1
a
: a resting stage of a plant (such as the lily, onion, hyacinth, or tulip) that is usually formed underground and consists of a short stem base bearing one or more buds enclosed in overlapping membranous or fleshy leaves
b
: a fleshy structure (such as a tuber or corm) resembling a bulb in appearance
c
: a plant having or developing from a bulb
2
: a bulb-shaped part
specifically
: a glass envelope enclosing the light source of an electric lamp or such an envelope together with the light source it encloses
3
: a rounded or swollen anatomical structure
4
: a camera setting that indicates that the shutter can be opened by pressing on the release and closed by ending the pressure
bulblike
adjective
or bulb-like
… a large underground rhizome, a bulblike growth that extends massive roots from its underside.
—Elizabeth Schneider
Cite this Entry
“Bulb.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/bulb. Accessed 1 Sep. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
