Definition of "bulb" []

• Botany A short, modified, underground stem surrounded by usually fleshy modified leaves that contain stored food for the shoot within: an onion bulb; a tulip bulb. (noun)
• Botany A similar underground stem or root, such as a corm, rhizome, or tuber. (noun)
• Botany A plant that grows from a bulb. (noun)
• A rounded projection or part: the bulb of a syringe. (noun)
• An incandescent lamp or its glass housing. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Only works if the bulb is actually "on", as in: plugged in or not burned out, The water keeps flowing, safe to drink or not."
• "I would love to convert to fluorescent, but at least half the time the bulb is an unacceptable tint."
• "Ban the bulb is a no-brainer, only this time the empty-headed variety."