[fahy-bruh l, fib-ruh l]
  1. a small or fine fiber or filament.
  2. Botany. any of the delicate hairs on the young roots of some plants.
  3. Cell Biology. any threadlike structure or filament.

Origin of fibril

1655–65; < New Latin fibrilla, equivalent to Latin fibr(a) fiber + -illa diminutive suffix
Related formsfi·bril·lar, adjectivefi·bril·lose, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for fibrillar

Historical Examples of fibrillar

British Dictionary definitions for fibrillar


fibrilla (faɪˈbrɪlə, fɪ-)

noun plural -brils or -brillae (-ˈbrɪliː)
  1. a small fibre or part of a fibre
  2. biology a threadlike structure, such as a root hair or a thread of muscle tissue
Derived Formsfibrilar, fibrillar or fibrillose, adjectivefibrilliform, adjective

Word Origin for fibril

C17: from New Latin fibrilla a little fibre
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fibrillar



1680s, back-formation from Modern Latin fibrilla, diminutive of Latin fibra (see fiber).

Online Etymology Dictionary, © 2010 Douglas Harper

fibrillar in Medicine


[fībrə-lər, fĭbrə-]
  1. Relating to a fibril.
  2. Relating to the fine rapid contractions or twitchings of fibers or of small groups of fibers in skeletal or cardiac muscle.


[fībrəl, fĭbrəl]
  1. A minute fiber.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

fibrillar in Science


[fībrəl, fĭbrəl]
  1. Any of various threadlike fibers or filaments that are constituent parts of a cell or larger structure. Cellulose fibrils are the main component of cell walls in plants. Fibrils make up the contractile part of striated muscle fiber in the body.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.