: a grayish or reddish granular cell that is the fundamental functional unit of nervous tissue transmitting and receiving nerve impulses and having cytoplasmic processes which are highly differentiated frequently as multiple dendrites or usually as solitary axons which conduct impulses to and away from the cell body : nerve cell sense 1

Illustration of neuron

Illustration of neuron
  • 1 cell body
  • 2 dendrite
  • 3 axon
  • 4 nerve ending

Examples of neuron in a Sentence

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Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
But signals recorded from neurons can change over time, creating a major problem for systems intended to work reliably every day. — Neetika Walter, Interesting Engineering, 2 Oct. 2026 It’s made up of tens of billions of neurons, each of which can form connections to its neighbors. — Victor Tangermann, Futurism, 24 Sep. 2026 By the time the first cells that are committed to develop into neurons show up, the vertebrate embryo already knows its head from its tail, and its back from its belly. — John Timmer, ArsTechnica, 23 Sep. 2026 The discovery explains why attempts in the past to develop hindbrain neurons from ectoderm stem cells failed – those cells had already been locked in as forebrain or midbrain neurons. — Mike McRae 21, New Atlas, 22 Sep. 2026 See All Example Sentences for neuron

Word History

Etymology

borrowed from German Neuron, borrowed from Greek neûron "sinew, tendon, nerve" — more at nerve entry 1

Note: Term introduced by the German anatomist Heinrich Wilhelm Waldeyer (Heinrich Wilhelm Gottfried von Waldeyer-Hartz, 1836-1921) in "Ueber einige neuere Forschungen im Gebiete der Anatomie der Centralnervensystems," Berliner klinische Wochenschrift, 28. Jahrgang, no. 28, July 13, 1891, p. 691: "Somit besteht ein Nervenelement (eine 'Nerveneinheit' oder 'Neuron', wie ich es zu nennen vorschlagen möchte), den genannten Forschungsergebnissen … zufolge, aus nachstehenden Stücken: a) einer Nervenzelle, b) dem Nervenfortsatze, c) dessen Collateralen und d) dem Endbäumchen." — "Therefore, in accordance with the cited research results, a nerve element (a 'nerve unit' or 'neuron,' as I would like to suggest as a name), consists of the following parts: a) a nerve cell, b) the nerve process [= axon], c) its collaterals and d) the end tree [= axon terminals]." Waldeyer apparently intended -on to be taken as a suffix, indicating a unit, rather than the Greek neuter singular inflectional ending, as he utilized Neuronen as the plural in the same article. Cf. French neurone and the English variant neurone.

First Known Use

1891, in the meaning defined above

Time Traveler
The first known use of neuron was in 1891

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Cite this Entry

“Neuron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neuron. Accessed 3 Oct. 2026.

Kids Definition

: a grayish or reddish cell that is the basic working unit of the nervous system and has an axon and dendrites that carry nerve impulses

Medical Definition

: one of the cells that constitute nervous tissue, that have the property of transmitting and receiving nerve impulses, and that are composed of somewhat reddish or grayish protoplasm with a large nucleus containing a conspicuous nucleolus, irregular cytoplasmic granules, and cytoplasmic processes which are highly differentiated frequently as multiple dendrites or usually as solitary axons and which conduct impulses toward and away from the cell body : nerve cell sense 1

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