fas·​cic·​u·​lus fə-ˈsi-kyə-ləs How to pronounce fasciculus (audio)
plural fasciculi fə-ˈsi-kyə-ˌlī How to pronounce fasciculus (audio)
: a slender bundle of anatomical fibers (such as nerve fibers)

Example Sentences

Recent Examples on the Web But the children in the two groups exhibited differences in the arcuate fasciculus and the ILF: In strong readers, these nerve connections started weak, then strengthened; the neuron bundles got more myelinated. Ashley P. Taylor, Discover Magazine, 10 Oct. 2012 This scan shows the difference between a control brain scan (yellow) and the scan of vets (red) in the right inferior fronto-occipital fasciculus. Florence Williams, Discover Magazine, 30 July 2014 In particular, damage to a bundle of axons called the right inferior fronto-occipital fasciculus correlated with the severity of pain and fatigue. Gemma Tarlach, Discover Magazine, 20 Mar. 2013 Our mental calendar involves circuits in the left angular gyrus, important for sequence discrimination and connected to the same hippocampal place cell or grid cell via a band of fibers: the inferior longitudinal fasciculus. Scientific American, 1 June 2020 This view shows the three major tracts involved with language and literacy skills: the arcuate fasciculus, shaded in white, which connects brain areas involved with receptive and expressive language. Sandee Lamotte, CNN, 4 Nov. 2019 Connecting Broca’s area with Wernicke’s is a neural network: a thick, curving bundle of billions of nerve fibres, the arcuate fasciculus, which integrates the production and the comprehension of language. Rachel Aviv, The New Yorker, 25 May 2018 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'fasciculus.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


New Latin, from Latin

First Known Use

1713, in the meaning defined at sense 1

Time Traveler
The first known use of fasciculus was in 1713

Dictionary Entries Near fasciculus

Cite this Entry

“Fasciculus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fasciculus. Accessed 31 Mar. 2023.

Medical Definition


fas·​cic·​u·​lus fə-ˈsik-yə-ləs, fa- How to pronounce fasciculus (audio)
plural fasciculi -ˌlī How to pronounce fasciculus (audio)
: a slender bundle of fibers:
: a bundle of skeletal muscle cells bound together by fasciae and forming one of the constituent elements of a muscle
: a bundle of nerve fibers that follow the same course but do not necessarily have like functional connections (as in some subdivisions of the funiculi of the spinal cord) compare tract sense 2
Last Updated: - Updated example sentences
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