bulb Meaning and Definition

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

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

3. n. a rounded dilation or expansion in a canal or vessel or organ

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

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