bulb

play
noun \ˈbəlb\

Definition of bulb

  1. 1a :  a resting stage of a plant (such as the lily, onion, hyacinth, or tulip) that is usually formed underground and consists of a short stem base bearing one or more buds enclosed in overlapping membranous or fleshy leavesb :  a fleshy structure (such as a tuber or corm) resembling a bulb in appearancec :  a plant having or developing from a bulb

  2. 2 :  a bulb-shaped part; specifically :  a glass envelope enclosing the light source of an electric lamp or such an envelope together with the light source it encloses

  3. 3 :  a rounded or swollen anatomical structure

  4. 4 :  a camera setting that indicates that the shutter can be opened by pressing on the release and closed by ending the pressure

bulbed

play \ˈbəlbd\ adjective

Examples of bulb in a Sentence

  1. the bulb of the thermometer

Recent Examples of bulb from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'bulb'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of bulb

Origin and Etymology of bulb

Middle English, from Latin bulbus, from Greek bolbos bulbous plant



BULB Defined for English Language Learners

bulb

play
noun

Definition of bulb for English Language Learners

  • : a rounded part of some plants that is under the ground and that grows into a new plant during the growing season

  • : a part that has a rounded shape


BULB Defined for Kids

bulb

play
noun \ˈbəlb\

Definition of bulb for Students

  1. 1 :  light bulb

  2. 2 :  a dormant stage of a plant that is formed underground and consists of a very short stem with one or more flower buds surrounded by special thick leaves

  3. 3 :  a plant structure (as a tuber) that is somewhat like a bulb

  4. 4 :  a rounded object or part the bulb of a thermometer


Medical Dictionary

bulb

play
noun \ˈbəlb\

Medical Definition of bulb

  1. 1:  a rounded dilation or expansion of something cylindrical the bulb of a thermometer; especially :  a rounded or pear-shaped enlargement on a small base the bulb of an eyedropper

  2. 2:  a rounded part: asa:  a rounded enlargement of one end of a part—see bulb of the penis, bulb of the vestibule, end bulb, hair bulb, olfactory bulbb:  medulla oblongata; broadly :  the hindbrain exclusive of the cerebellumc:  a thick-walled muscular enlargement of the pharynx of certain nematode worms


Learn More about bulb


Seen and Heard

What made you want to look up bulb? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

to be a fixed element or attribute

Get Word of the Day daily email!

Test Your Vocabulary

July 2017 Words of the Day Quiz

  • alt-597a99e699d07
  • Which is a synonym of gauche?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!