quantum

[ kwon-tuhm ]

noun

, plural quan·ta [kwon, -t, uh].

1. quantity or amount:

   the least quantum of evidence.

2. a particular amount.
3. a share or portion.
4. a large quantity; bulk.
5. Physics.
   1. the smallest quantity of radiant energy, equal to Planck's constant times the frequency of the associated radiation.
   2. the fundamental unit of a quantized physical magnitude, as angular momentum.

adjective

1. sudden and significant:

   a quantum increase in productivity.

quantum

/ ˈkwɒntəm /

noun

1. physics
   1. the smallest quantity of some physical property, such as energy, that a system can possess according to the quantum theory
   2. a particle with such a unit of energy
2. amount or quantity, esp a specific amount
3. often used with a negative the least possible amount that can suffice

   there is not a quantum of evidence for your accusation

4. something that can be quantified or measured
5. modifier loosely, sudden, spectacular, or vitally important

   a quantum improvement

quantum

/ kwŏn′təm /

, 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.
2. See also quantum state

Word History and Origins

Origin of quantum¹

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

Word History and Origins

Origin of quantum¹

C17: from Latin quantus (adj) how much