| electric lamp consisting of a transparent or translucent glass housing containing a wire filament (usually tungsten) that emits light when heated by electricity | thermometer consisting of mercury contained in a bulb at the bottom of a graduated sealed glass capillary tube marked in degrees Celsius or Fahrenheit; mercury expands with a rise in temperature causing a thin thread of mercury to rise in the tube |
| a rounded part of a cylindrical instrument (usually at one end) | |
| a rounded dilation or expansion in a canal or vessel or organ | |
| 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 | |