Meaning of o'clock

o'clock

Pronunciation: (u-klok'), [key]
— adv.
  1. of, by, or according to the clock (used in specifying the hour of the day): It is now 4 o'clock.
  2. according to a method for indicating relative position whereby a plane in space is considered to be numbered as a clock's face, with 12 o'clock considered as directly ahead in horizontal position or straight up in vertical position.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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