adverb Etymology: contraction of of the clock Date: 1535 according to the clock , 2. — used for indicating position or direction as if on a clock dial that is oriented vertically or horizontally
O'CLOCK
Meaning of O'CLOCK in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012