quantum

n. amount; particular quantity; part, portion; large quantity; basic unit of radiant energy (Physics)

Development of quantum theory Quantum theory, the branch of physics which is based on quantization, began in 1900 when Max Planck published his theory explaining the emission spectrum of black bodies. In that paper Planck used the Natural system of units he invented the previous year. The consequences of the differences between classical and quantum mechanics quickly became obvious. But it was not until 1926, by the work of Werner Heisenberg, Erwin Schrödinger, and others, that quantum mechanics became correctly formulated and understood mathematically. Despite tremendous experimental success, the philosophical interpretations of quantum theory are still widely debated.
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Quantum /quan·tum/ pl. quan´ta [L.] a unit of measure under the quantum theory. quan·tum n. pl. quan·ta 1. [more]Quantum - Community and Resources

Noun
1. a discrete amount of something that is analogous to the quantum in quantum theory
(hypernym) quantity
2. (physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory)
(hypernym) measure, quantity, amount
(hyponym) quasiparticle
(classification) physics, physical science, natural philosophy

n. quantum, amount, particular quantity, portion, part; (Physics) basic unit of radiant energy