Main Entry:

o'·clock

Pronunciation:

\ə-ˈkläk, ō-\

Function:

adverb

Etymology:

contraction of of the clock

Date:

1535

1 : according to the clock <the time is three o'clock> 2 —used for indicating position or direction as if on a clock dialect that is oriented vertically or horizontally <an airplane approaching at six o'clock>