bulb
noun
1.
a modified bud consisting of a thickened globular underground stem serving as a reproductive structure
Derived from:
bulbaceous 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.
4.
5.
lower or hindmost part of the brain; continuous with spinal cord; (‘bulb’ is an old term for medulla oblongata)
Derived from:
bulbar 6.