bulb

noun \ˈbəlb\

: a rounded part of some plants that is under the ground and that grows into a new plant during the growing season

: a part that has a rounded shape

Full Definition of BULB

a : a resting stage of a plant (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 (as a tuber or corm) resembling a bulb in appearance

c : a plant having or developing from a bulb

: 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

: a rounded or swollen anatomical structure

: a camera setting that indicates that the shutter can be opened by pressing on the release and closed by ending the pressure

— bulbed \ˈbəlbd\ adjective

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Illustration of BULB

Origin of BULB

Middle English, from Latin bulbus, from Greek bolbos bulbous plant

First Known Use: 15th century

BULBED Defined for Kids

bulb

noun \ˈbəlb\

Definition of BULB for Kids

: light bulb

: a dormant stage of a plant that is formed underground and consists of a very short stem with one or more flower buds surrounded by special thick leaves

: a plant structure (as a tuber) that is somewhat like a bulb

: a rounded object or part <the bulb of a thermometer>

Medical Dictionary

bulb

noun \ˈbəlb\

Medical Definition of BULB

: a rounded dilation or expansion of something cylindrical <the bulb of a thermometer>; especially : a rounded or pear-shaped enlargement on a small base <the bulb of an eyedropper>

: a rounded part: as a : a rounded enlargement of one end of a part—see bulb of the penis, bulb of the vestibule, end bulb, hair bulb, olfactory bulb b : medulla oblongata; broadly : the hindbrain exclusive of the cerebellum c : a thick-walled muscular enlargement of the pharynx of certain nematode worms