lambda

noun lamb·da \ ˈlam-də \

Definition of lambda

1 : the 11th letter of the Greek alphabet — see Alphabet Table

2 : an uncharged unstable elementary particle that has a mass 2183 times that of an electron and that decays typically into a nucleon and a pion

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Recent Examples of lambda from the Web

The Xi decays into a particle called the lambda baryon and three lighter particles, the K- (or kaon) and two pions.

— Fox News, "‘Charming’ heavy particle discovered at world’s largest atom smasher," 11 July 2017
However, the name is trademarked, and the project opted instead for lambda — the Greek letter used to symbolize wavelength.

— wired staff, WIRED, "Fast Track for Science Data," 17 Nov. 2003

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

Origin and Etymology of lambda

Middle English, from Greek, of Semitic origin; akin to Hebrew lāmedh lamed

NEW! Time Traveler

First Known Use: 15th century

in the meaning defined at sense 1

See Words from the same year

Medical Dictionary

lambda

noun lamb·da \ ˈlam-də \

medical Definition of lambda

1 : the point of junction of the sagittal and lambdoid sutures of the skull

2 : bacteriophage lambda

Illustration of lambda

Learn More about lambda

Britannica.com: Encyclopedia article about lambda

Seen and Heard

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