What is the meaning of Bulb?

The bulb-shaped root portion of a plant such as a tulip, from which the rest of the plant may be regrown.

The medulla oblongata.

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.

An onion.

To take the shape of a bulb; to swell.

bulb (bulb-shaped root of a plant)

bulb

Source: wiktionary.org