ex·tra·sys·to·le 
(ĕk′strə-sĭstə-lē)
(ĕk′strə-sĭstə-lē)n.
A premature contraction of the heart, resulting in momentary cardiac arrhythmia.
ex′tra·sys·tolic (-sĭ-stŏlĭk) adj.
- out of the question
- out of the running
- out-of-the-way
- out of the way
- out of the woods
- out of the woodwork
- out of this world
- out-of-touch
- out of touch
- out-of-town
- out-of-towner
- out of turn
- out of wedlock
- out of whack
- out of whole cloth
- out of work
- (out) on a limb
- out on a limb
- outpace
- outpatient
- outperform
- outperformance
- outplace
- outplacement
- outplay