bulb

noun

• 1a rounded underground storage organ present in some plants, notably those of the lily family, consisting of a short stem surrounded by fleshy scale leaves or leaf bases, lying dormant over winter. Compare with corm, rhizome.
• a plant grown from a bulb.

• 2short for light bulb.

• 3an expanded part of a glass tube such as that forming the reservoir of a thermometer.
• a hollow flexible container with an opening through which the air can be expelled by squeezing, such as that used to fill a syringe.
• a spheroidal dilated part at the end of an anatomical structure.