five o'clock
noun1
The start of the sixth hour of the day; 5:00 a.m. (05:00).
In both the 12-hour clock and the 24-hour clock
- The breakfast buffet opens at five o'clock (= "The breakfast buffet opens at 5:00 a.m.").
2
The start of the eighteenth hour of the day; 5:00 p.m. (17:00).
Only in the 12-hour clock
- The next train comes at five o'clock (= "The next train comes at 17:00").
3
Informal A position behind and slightly to the right (horizontal clock orientation) (from the location of the 5 mark on a clock face)
- We've got a bogey at five o'clock.
- Derived terms
- five o’clock shadow, it's five o'clock somewhere