fasciculus

noun

fas·​cic·​u·​lus fə-ˈsi-kyə-ləs 

fa-

plural fasciculi fə-ˈsi-kyə-ˌlī 

fa-

1

: a slender bundle of anatomical fibers (such as nerve fibers) : fascicle sense 1b

2

: one of the divisions of a book published in parts : fascicle sense 2

Examples of fasciculus in a Sentence

Recent Examples on the Web

Brain imaging studies of criminality going back to 2009 have suggested that damage to a swath of white matter called the right uncinate fasciculus is somehow involved when people commit violent acts. —Christopher M. Filley, The Conversation, 3 Feb. 2026

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

The vertical occipital fasciculus, or VOF, is identified in a postmortem human brain in 1909, but labeled with a different name. —Jenny Blair, Discover Magazine, 1 Oct. 2015

Word History

Etymology

New Latin, from Latin

First Known Use

1713, in the meaning defined at sense 1

Rhymes for fasciculus

• colliculus
• meticulous
• ridiculous

Medical Definition

fasciculus

noun

fas·​cic·​u·​lus fə-ˈsik-yə-ləs, fa- 

plural fasciculi -ˌlī 

: a slender bundle of anatomical fibers:

a

: a bundle of skeletal muscle cells surrounded by perimysium and forming one of the constituent elements of a muscle

b

: a bundle of nerve fibers surrounded by perineurium

specifically : a bundle of nerve fibers having a common origin, termination, and function : tract sense 2