: a fine proteinaceous fibril that is found in cytoplasm (as of a neuron or a paramecium) and is capable of conducting excitation

Word History

Etymology

borrowed from German Neurofibrille, from neuro- neuro- + Fibrille fibril

First Known Use

1898, in the meaning defined above

Time Traveler
The first known use of neurofibril was in 1898

Browse Nearby Words

Cite this Entry

“Neurofibril.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neurofibril. Accessed 7 Jul. 2026.

Medical Definition

: a fine proteinaceous fibril that is found in cytoplasm (as of a neuron) and is capable of conducting excitation
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