BULB

Pronunciation (US):

(GB):

IPA (US):

 Dictionary entry overview: What does bulb mean? 

• BULB (noun)
  The noun BULB has 6 senses:

1. a modified bud consisting of a thickened globular underground stem serving as a reproductive structure

2. electric lamp consisting of a transparent or translucent glass housing containing a wire filament (usually tungsten) that emits light when heated by electricity

3. a rounded part of a cylindrical instrument (usually at one end)

4. anything with a round shape resembling a teardrop

5. lower or hindmost part of the brain; continuous with spinal cord; ('bulb' is an old term for medulla oblongata)

6. a rounded dilation or expansion in a canal or vessel or organ

  Familiarity information: BULB used as a noun is common.

 Dictionary entry details 

• BULB (noun)

Sense 1

Meaning:

A modified bud consisting of a thickened globular underground stem serving as a reproductive structure

Classified under:

Nouns denoting plants

Hypernyms ("bulb" is a kind of...):

stalk; stem (a slender or elongated structure that supports a plant or fungus or a plant part or plant organ)

Hyponyms (each of the following is a kind of "bulb"):

onion (the bulb of an onion plant)

shallot (aggregate bulb of the multiplier onion)

squill (bulb of the sea squill, which is sliced, dried, and used as an expectorant)

bulbil; bulblet (small bulb or bulb-shaped growth arising from the leaf axil or in the place of flowers)

Derivation:

bulbaceous (producing or growing from bulbs)

Sense 2

Meaning:

Electric lamp consisting of a transparent or translucent glass housing containing a wire filament (usually tungsten) that emits light when heated by electricity

Classified under:

Nouns denoting man-made objects

Synonyms:

bulb; electric-light bulb; electric light; incandescent lamp; light bulb; lightbulb

Hypernyms ("bulb" is a kind of...):

electric lamp (a lamp powered by electricity)

Meronyms (parts of "bulb"):

filament (a thin wire (usually tungsten) that is heated white hot by the passage of an electric current)

Sense 3

Meaning:

A rounded part of a cylindrical instrument (usually at one end)

Classified under:

Nouns denoting man-made objects

Context example:

the bulb of a syringe

Hypernyms ("bulb" is a kind of...):

part; portion (something less than the whole of a human artifact)

Holonyms ("bulb" is a part of...):

mercury-in-glass thermometer; mercury thermometer (thermometer consisting of mercury contained in a bulb at the bottom of a graduated sealed glass capillary tube marked in degrees Celsius or Fahrenheit; mercury expands with a rise in temperature causing a thin thread of mercury to rise in the tube)

syringe (a medical instrument used to inject or withdraw fluids)

Derivation:

bulbous (shaped like a bulb)

Sense 4

Meaning:

Anything with a round shape resembling a teardrop

Classified under:

Nouns denoting two and three dimensional shapes

Hypernyms ("bulb" is a kind of...):

round shape (a shape that is curved and without sharp angles)

Derivation:

bulblike (shaped like a bulb)

Sense 5

Meaning:

Lower or hindmost part of the brain; continuous with spinal cord; ('bulb' is an old term for medulla oblongata)

Classified under:

Nouns denoting body parts

Synonyms:

bulb; medulla; medulla oblongata

Context example:

the medulla oblongata is the most vital part of the brain because it contains centers controlling breathing and heart functioning

Hypernyms ("bulb" is a kind of...):

neural structure (a structure that is part of the nervous system)

Meronyms (parts of "bulb"):

respiratory center (the center in the medulla oblongata and pons that integrates sensory information about the level of oxygen and carbon dioxide in the blood and determines the signals to be sent to the respiratory muscles)

Holonyms ("bulb" is a part of...):

brain-stem; brain stem; brainstem (the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus)

Derivation:

bulbar (involving the medulla oblongata)

Sense 6

Meaning:

A rounded dilation or expansion in a canal or vessel or organ

Classified under:

Nouns denoting body parts

Hypernyms ("bulb" is a kind of...):

anatomical structure; bodily structure; body structure; complex body part; structure (a particular complex anatomical part of a living thing and its construction and arrangement)

Derivation:

bulbous (curving outward)

 Context examples 

Neuregulin-2 is primarily found in granule cells in the cerebellum, hippocampus, and olfactory bulb.

(Neuregulin 2, NCI Thesaurus)

It is lined with ciliated, pseudostratified columnar epithelium and functions to humidify, heat, and filter incoming air, as well as protecting the olfactory bulb and sinuses from incorrectly pressurized incoming air.

(Nasal Turbinate, NCI Thesaurus)

He looked sober in spite of his humming, till he went to the window to turn the hyacinth bulbs toward the sun, and stroke the cat, who received him like an old friend.

(Little Women, by Louisa May Alcott)

There are two olfactory bulbs on the bottom side of the brain, one above each nasal cavity.

(Olfactory bulb, NCI Dictionary)

The accessory olfactory bulb, which receives the projection from the VOMERONASAL ORGAN via the vomeronasal nerve, is also included here.

(Olfactory bulb, NLM, Medical Subject Headings)

The axons of olfactory receptor cells extend into the olfactory bulb.

(Olfactory bulb, NCI Thesaurus)

The lower portion of a hair follicle from the base of the bulb to the arrector pili muscle.

(Hair Follicle Inferior Segment, NCI Thesaurus)

It is characterized by the formation of pseudo-onion bulbs by the proliferating perineural cells.

(Intraneural Perineurioma, NCI Thesaurus)

A European plant that has a bulb used to flavor food.

(Allium sativum, NCI Dictionary)

Garlic plants produce an underground bulb that usually is divisible into 6-20 segments, called cloves.

(Allium sativum, NCI Thesaurus)