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noun \ˈbəlb\

Simple Definition of bulb

  • : 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

  1. 1 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

  2. 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. 3 :  a rounded or swollen anatomical structure

  4. 4 :  a camera setting that indicates that the shutter can be opened by pressing on the release and closed by ending the pressure

bulbed play \ˈbəlbd\ adjective

Examples of bulb

  1. the bulb of the thermometer

Illustration of bulb

Origin of bulb

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

First Known Use: 15th century

Medical Dictionary


noun \ˈbəlb\

Medical Definition of bulb

  1. 1:  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>

  2. 2:  a rounded part: asa:  a rounded enlargement of one end of a part—see bulb of the penis, bulb of the vestibule, end bulb, hair bulb, olfactory bulbb:  medulla oblongata; broadly :  the hindbrain exclusive of the cerebellumc:  a thick-walled muscular enlargement of the pharynx of certain nematode worms


combining form

Medical Definition of bulb-

  1. 1:  bulb <bulbar>

  2. 2:  bulbar and <bulbospinal> <bulbourethral gland>

Variants of bulb-

or bulbo-

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February 8, 2016

to clear from accusation or blame

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