o'clock

[uh-klok]

adverb

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.

o'clock

/ əˈklɒk /

adverb

1. used after a number from one to twelve to indicate the hour of the day or night

2. used after a number to indicate direction or position relative to the observer, twelve o'clock being directly ahead or overhead and other positions being obtained by comparisons with a clock face

Word History and Origins

Origin of o'clock¹

First recorded in 1710–20; from o', a reduced form of of; o' + clock ¹ ( def. )

Word History and Origins

Origin of o'clock¹

C18: abbreviation for of the clock