mass·​less | \ ˈmas-ləs How to pronounce massless (audio) \

Definition of massless

: having no mass a massless particle

Examples of massless in a Sentence

Recent Examples on the Web

They're known for traveling at near lightspeeds and being nearly massless, but a new study has shown the masslessness of the most massless neutrino. David Grossman, Popular Mechanics, "Ghost Particles Could Explain Just About Everything in the Universe," 23 Aug. 2019 Neutrinos are nearly massless subatomic particles that have no electric charge and therefore interact rarely with their surroundings. Mike Wall, NBC News, "High-energy 'ghost particle' traced to distant galaxy in astronomy breakthrough," 12 July 2018 Models at the time predicted that certain fundamental particles would be massless, but the mechanism that the three physicists proposed explained how these particles could have mass. Steph Yin, New York Times, "Tom Kibble, Physicist Who Helped Discover the Higgs Mechanism, Dies at 83," 19 July 2016 Such flavor changing shows that neutrinos cannot be massless. Adrian Cho, Science | AAAS, "Weighing the universe's most elusive particle," 29 June 2017

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

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First Known Use of massless

1879, in the meaning defined above

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Statistics for massless

Last Updated

27 Aug 2019

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Time Traveler for massless

The first known use of massless was in 1879

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Rhyming Dictionary: Words that rhyme with massless

Comments on massless

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


one from the Upper Peninsula of Michigan

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