Bulb

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

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

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

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

anything with a round shape resembling a teardrop

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