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Simple Definition of quantum

from our Learner's Dictionary

quantum

1 of 2

noun

ˈkwɑːntəm

plural quanta ˈkwɑːntə

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

quantum

2 of 2

adjective

always used before a noun

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

quantum physics

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“Quantum.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/quantum. Accessed 18 Jun. 2026.

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Simple Definition of quantum

quantum

noun

adjective

Cite this Entry

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