[ kwon-tuhm ]
See synonyms for: quantumquanta on Thesaurus.com

noun,plural quan·ta [kwon-tuh]. /ˈkwɒn tə/.
  1. quantity or amount: the least quantum of evidence.

  2. a particular amount.

  1. a share or portion.

  2. a large quantity; bulk.

  3. Physics.

    • the smallest quantity of radiant energy, equal to Planck's constant times the frequency of the associated radiation.

    • the fundamental unit of a quantized physical magnitude, as angular momentum.

  1. sudden and significant: a quantum increase in productivity.

Origin of quantum

1610–20; noun use of neuter of Latin quantus how much

Words Nearby quantum

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use quantum in a sentence

British Dictionary definitions for quantum


/ (ˈkwɒntəm) /

nounplural -ta (-tə)
  1. physics

    • the smallest quantity of some physical property, such as energy, that a system can possess according to the quantum theory

    • a particle with such a unit of energy

  2. amount or quantity, esp a specific amount

  1. (often used with a negative) the least possible amount that can suffice: there is not a quantum of evidence for your accusation

  2. something that can be quantified or measured

  3. (modifier) loosely, sudden, spectacular, or vitally important: a quantum improvement

Origin of quantum

C17: from Latin quantus (adj) how much

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for quantum


[ kwŏntəm ]

Plural quanta
  1. A discrete, indivisible manifestation of a physical property, such as a force or angular momentum. Some quanta take the form of elementary particles; for example, the quantum of electromagnetic radiation is the photon, while the quanta of the weak force are the W and Z particles. See also quantum state.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.