one o'clock
noun1
The start of the second hour of the day; 1:00 a.m. (01:00).
In both the 12-hour clock and the 24-hour clock
- The bar closes at one o'clock (= "The bar closes at 1:00 a.m.").
2
The start of the fourteenth hour of the day; 1:00 p.m. (13:00).
Only in the 12-hour clock
- The next train comes at one o'clock (= "The next train comes at 13:00").
3
Informal A position ahead and slightly rightward (horizontal clock orientation) or almost directly above (vertical clock orientation) (from the location of the 1 mark on a clock face)
- We've got a bogey at one o'clock.
4
Informal A dandelion.
- Derived terms
- like one o'clock, like one o'clock half struck