[ fahy-bruh l, fib-ruh l ]
/ ˈfaɪ brəl, ˈfɪb rəl /


a small or fine fiber or filament.
Botany. any of the delicate hairs on the young roots of some plants.
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 forms

fi·bril·lar, adjectivefi·bril·lose, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fibrillar

British Dictionary definitions for fibrillar


fibrilla (faɪˈbrɪlə, fɪ-)

/ (ˈfaɪbrɪl) /

noun plural -brils or -brillae (-ˈbrɪliː)

a small fibre or part of a fibre
biology a threadlike structure, such as a root hair or a thread of muscle tissue

Derived Forms

fibrilar, 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

Medicine definitions for fibrillar (1 of 2)


[ fībrə-lər, fĭbrə- ]


Relating to a fibril.
Relating to the fine rapid contractions or twitchings of fibers or of small groups of fibers in skeletal or cardiac muscle.

Medicine definitions for fibrillar (2 of 2)


[ fībrəl, fĭbrəl ]


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

Science definitions for fibrillar


[ fībrəl, fĭbrəl ]

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.