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1. Electric lamp consisting of a transparent or translucent glass housing containing a wire filament (usually tungsten) that emits light when heated by electricity
   - light bulb, lightbulb, incandescent lamp, electric light, electric-light bulb, light globe [Austral, NZ]
    
2. A modified bud consisting of a thickened globular underground stem serving as a reproductive structure
    
3. A rounded part of a cylindrical instrument (usually at one end)
   "the bulb of a syringe"
    
4. Anything with a round shape resembling a teardrop
    
5. A rounded dilation or expansion in a canal or vessel or organ
    
6. [archaic] Lower or hindmost part of the brain; continuous with spinal cord
   "the bulb is the most vital part of the brain because it contains centres controlling breathing and heart functioning";
   - medulla oblongata, medulla

Derived forms: bulbs

Type of: anatomical structure, bodily structure, body structure, complex body part, electric lamp, neural structure, part, portion, round shape, stalk, stem, structure

Part of: brain stem, brainstem, brain-stem, mercury thermometer, mercury-in-glass thermometer, syringe

Encyclopedia: Bulb