quan·​tum | \ ˈkwän-təm How to pronounce quantum (audio) \
plural quanta\ ˈkwän-​tə How to pronounce quanta (audio) \

Definition of quantum

 (Entry 1 of 2)

c : gross quantity : bulk
2a : any of the very small increments or parcels into which many forms of energy are subdivided
b : any of the small subdivisions of a quantized physical magnitude (such as magnetic moment)



Definition of quantum (Entry 2 of 2)

1 : large, significant a quantum improvement
2 : of, relating to, or employing the principles of quantum mechanics quantum physics

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Synonyms for quantum

Synonyms: Noun

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Examples of quantum in a Sentence

Noun the sum of human knowledge is now so immense that even a highly educated person can hope to absorb only a tiny quantum of it
Recent Examples on the Web: Noun Besides the infra boost, the government has proposed an investment of Rs8,000 crore ($1.1 billion) over five years in its national mission on quantum technologies and applications. Ananya Bhattacharya, Quartz India, "Budget 2020’s push for startups shows that entrepreneurship is serious business in India," 3 Feb. 2020 Its small group of quantum researchers is not building its own quantum computing hardware. Tom Simonite, Wired, "Alphabet Has a Second, Secretive Quantum Computing Team," 31 Jan. 2020 The transition between the quantum and the familiar seems to be set by environmental interactions. John Timmer, Ars Technica, "Levitating sand escapes classical world, enters quantum ground state," 31 Jan. 2020 This realization is what defines research in higher-dimensional quantum systems. Urbasi Sinha, Scientific American, "Quantum Slits Open New Doors," 7 Jan. 2020 In a collection lawsuit over a surprise medical bill, a provider (the plaintiff in these suits) must prove that a service was delivered to the patient and also demonstrate the value of that service (quantum meruit in legal terms). Jackson Williams, STAT, "3 legal challenges could derail out-of-network surprise medical bills," 6 Jan. 2020 There, mass breaks down to its most fundamental state: quantum particles. Maria Paula Rubiano, Popular Science, "What would happen if you fell into a black hole?," 2 Jan. 2020 The principle of quantum superposition says that a particle can be in two places at the same time. Hart Pomerantz, The New Yorker, "Einstein: The Untold Story," 30 Dec. 2019 Scientists are using quantum technology to develop new kinds of computers and communications networks, and new sensors for imaging and measuring objects. Jeanne Whalen, Washington Post, "China’s top quantum scientist has ties to the country’s defense companies," 26 Dec. 2019 Recent Examples on the Web: Adjective But the increase in A.I. and quantum computing comes at a tradeoff to investing into other areas of science. Jonathan Vanian, Fortune, "White House proposes big increase in A.I. and quantum spending while cutting other sciences," 12 Feb. 2020 The technologies that promise to rule in the new digital age are distributed ledger technology, AI, extended reality (XR), and quantum computing. Keshav R. Murugesh, Quartz India, "What does “being digital” mean in a post-digital era?," 3 Feb. 2020 Exciting breakthroughs in fields from quantum computing to next-generation cars seem to be happening everywhere else. The Economist, "L’industrie, c’est eux Europe is rediscovering its penchant for statist intervention," 18 Jan. 2020 But millions of people around the world contribute to these communities to accelerate innovation in areas like artificial intelligence, blockchain, and quantum computing. Bob Lord, Quartz, "How open-source code could help us survive natural disasters," 14 Jan. 2020 Nick Offerman plays Forest, a mysterious CEO fixated on questions of how quantum computing might be able to change the future. Sophie Gilbert, The Atlantic, "The Most Unmissable TV Shows of 2020," 9 Jan. 2020 The triple-slit experiment is also helpful in quantum computing. Urbasi Sinha, Scientific American, "Quantum Slits Open New Doors," 7 Jan. 2020 Guo’s team believes, similarly, that DNA computing will join quantum computing as a method that can eventually outpace silicon-chip computing. Caroline Delbert, Popular Mechanics, "DNA Computer Can Calculate the Square Root of 900," 2 Jan. 2020 Google Cloud is looking to move quantum computing from the research space to industry. Emily Bamforth, cleveland, "Google Cloud CEO explains what makes new technologies last," 11 Dec. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'quantum.' 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 quantum


1567, in the meaning defined at sense 1a


1942, in the meaning defined at sense 1

History and Etymology for quantum


Latin, neuter of quantus how much

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Time Traveler for quantum

Time Traveler

The first known use of quantum was in 1567

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Statistics for quantum

Last Updated

13 Feb 2020

Cite this Entry

“Quantum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quanta. Accessed 21 Feb. 2020.

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More Definitions for quantum


How to pronounce quantum (audio)

English Language Learners Definition of quantum

 (Entry 1 of 2)

physics : the smallest amount of many forms of energy (such as light)



English Language Learners Definition of quantum (Entry 2 of 2)

physics : of, relating to, or using the principles of quantum theory


quan·​tum | \ ˈkwänt-əm How to pronounce quantum (audio) \
plural quanta\ ˈkwänt-​ə How to pronounce quanta (audio) \

Medical Definition of quantum

1 : one of the very small increments or parcels into which many forms of energy are subdivided a molecule of rhodopsin in the human eye can cause a response to a single quantum of light
2 : one of the small molecular packets of a neurotransmitter (as acetylcholine) released into the synaptic cleft in the transmission of a nerve impulse across a synapse

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