To take the shape of a bulb; to swell.
Any solid object rounded at one end and tapering on the other, possibly attached to a larger object at the tapered end.
A light bulb (not necessarily bulbous in shape).
A bulbous protuberance at the forefoot of certain vessels to reduce turbulence.
The bulb-shaped root portion of a plant such as a tulip, from which the rest of the plant may be regrown.