Definition
Some unspecified hour in the early morning (implying an unpleasant time to be awake).
Origins
From U.S. military terminology, in which hours before 10:00 am are prefixed with a zero, read as "oh", as in 0530, oh five-thirty, for 5:30 am.
In Context
- "I had to get up at oh dark thirty to catch a plane."
Also Said As
- crack of dawn
- dark o’clock
- stupid o'clock
- wee small hours
- see also Thesaurus:early morning
See Also
- 0-dark-hundred
- oh dark hundred
- beer o'clock