twelve o'clock
noun1
Usually The start of the thirteenth hour of the day; noon (noontime); 12:00 p.m. (12:00).
In both the 12-hour clock and the 24-hour clock
- The next train comes at twelve o'clock (= "The next train comes at noon").
2
Usually The start of the first hour of the day; midnight; 12:00 a.m. (00:00).
Only in the 12-hour clock
- The bar closes at twelve o'clock (= "The bar closes at midnight").
3
Informal, Usually A position straight ahead (horizontal clock orientation) or above (vertical clock orientation) (from the location of the 12 mark on a clock face)
- We've got a bogey at twelve o'clock (= "We've got a bogey straight in front of us").