twelve o'clock

noun3

1. •
   The start of the thirteenth hour of the day; noon (noontime); 12:00 p.m. (12:00).

   • The next train comes at twelve o'clock (= "The next train comes at noon").
2. •
   The start of the first hour of the day; midnight; 12:00 a.m. (00:00).

   • The bar closes at twelve o'clock (= "The bar closes at midnight").
3. •
   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").