bulb (n.)

  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

    [ Syn: light bulb , lightbulb , incandescent lamp , electric light , electric-light bulb ]

  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. lower or hindmost part of the brain; continuous with spinal cord; (`bulb is an old term for medulla oblongata); the medulla oblongata is the most vital part of the brain because it contains centers controlling breathing and heart functioning

    [ Syn: medulla oblongata , medulla ]

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

The dictionary is based on the WordNet Electronic Lexical Database.
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