WordReference Random House Unabridged Dictionary of American English © 2026
de•fi•bril•late
(dē fī′brə lāt′, -fib′rə-),USA pronunciation v.t., -lat•ed, -lat•ing. [Med.]
de•fi′bril•la′tion, n.
- Medicineto arrest the fibrillation of (heart muscle) by applying electric shock across the chest, thus depolarizing the heart cells and allowing normal rhythm to return.
- de- + fibrillate, back formation from fibrillation 1930–35