əˈkläk adverb
Etymology: contraction of of the clock
1. : according to the clock : by the clock
the time is three o'clock
2. : on a clock dial imagined in a horizontal position with the observer at the center facing the numeral 12 or in a vertical position in front of and facing the observer with the numeral 12 at the top — used for indicating position or direction
the pilot saw a plane approaching at eleven o'clock
a bullet hit the target at three o'clock