What is the meaning of Bulb?

The bulb-shaped underground portion of a plant such as a tulip, consisting of a shortened stem and many fleshy scale leaves, 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