quan·​tal ˈkwän-tᵊl How to pronounce quantal (audio)
[Latin quanti how many, plural of quantus] : of, relating to, or having only two experimental alternatives (such as dead or alive, all or none)
[quantum] : of or relating to a quantum

Did you know?

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).

Word History

First Known Use

1933, in the meaning defined at sense 1

Time Traveler
The first known use of quantal was in 1933


Dictionary Entries Near quantal

Cite this Entry

“Quantal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quantal. Accessed 15 Jun. 2024.

Medical Definition


quan·​tal ˈkwänt-ᵊl How to pronounce quantal (audio)
: of or relating to a quantum or to quanta (as of energy or a neurotransmitter)
quantal release of acetylcholine
: 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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!