quan·​tal | \ ˈkwän-tᵊl How to pronounce quantal (audio) \

Definition of quantal

1 [Latin quanti how many, plural of quantus] : of, relating to, or having only two experimental alternatives (such as dead or alive, all or none)
2 [quantum] : of or relating to a quantum

Get Quantitative With Quantum

In Latin, quantum is the neuter form of quantus, meaning "how much?" Both of these forms played a role in the development of quantal. The first sense of quantal, used in scientific experimentation to refer to cases in which only one of two possible results occurs, derived from quanti, the plural of quantus. (Quantus is also an ancestor of our noun quantity.) The second sense of quantal is more directly related to Latin quantum and the English noun quantum, which refers to the smallest possible unit of a form of energy (such as light).

First Known Use of quantal

1933, in the meaning defined at sense 1

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The first known use of quantal was in 1933

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Cite this Entry

“Quantal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quantal. Accessed 6 Oct. 2022.

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More Definitions for quantal


quan·​tal | \ ˈkwänt-ᵊl How to pronounce quantal (audio) \

Medical Definition of quantal

1 : of or relating to a quantum or to quanta (as of energy or a neurotransmitter) quantal release of acetylcholine
2 : being or relating to a sensitivity response marked by the presence or absence of a definite reaction an all-or-none response to a stimulus is quantal


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