n. A premature contraction of the heart, producing an interruption or irregularity in heartbeat rhythm, associated with heart disease or the use of some pharmaceuticals.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a premature systole resulting in a momentary cardiac arrhythmia
Word Usage
"Anyway, my new words: extrasystole as in “He asked me if it was like an extrasystole.”"