Dictionary.com
definitions

fibrillate

[fahy-bruh-leyt, fib-ruh-]

verb (used with object), fi·bril·lat·ed, fi·bril·lat·ing.

to cause to undergo fibrillation.

verb (used without object), fi·bril·lat·ed, fi·bril·lat·ing.

to undergo fibrillation.

Origin of fibrillate

First recorded in 1830–40; fibrill(a) + -ate1
Related formsfi·bril·la·tive, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Word Origin and History for fibrillated

fibrillate

v.

c.1840, from fibrilla (see fibril) + -ate (2). Related: Fibrillated; fibrillating.

Online Etymology Dictionary, © 2010 Douglas Harper
fibrillated in Medicine

fibrillated

[fĭb′rə-lā′tĭd, fī′brə-]

adj.

Composed of fibrils.

fibrillate

[fĭb′rə-lāt′, fī′brə-]

v.

To undergo or to cause to undergo fibrillation.
To make or to become fibrillar.

adj.

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