: 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

Recent Examples on the Web
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Sensory neurons carry information as traveling waves of electrical charge called action potentials — brief, self-propagating voltage spikes that move down the length of a nerve fiber. Scott Travers, Forbes.com, 1 Aug. 2026 The team also worked with flies genetically engineered so light could switch their olfactory neurons on directly, in both antennae at once. Jacek Krywko, ArsTechnica, 1 Aug. 2026 Increasing evidence suggests that toxic clumps of proteins called alpha-synuclein are among the primary drivers of damage to neurons. Sunil Kumar, The Conversation, 31 July 2026 The model behind most popular networks today is based on a neuron model from a 1943 paper, the McCulloch-Pitts model. Jackie Snow, IEEE Spectrum, 30 July 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 4 Aug. 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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