nine o'clock

Short definition from Wiktionary

Noun

1. 1
   The start of the tenth hour of the day; 9:00 a.m. (09:00).
2. 2
   The start of the twenty-second hour of the day; 9:00 p.m. (21:00).
3. 3
   To the left (horizontal clock orientation) (from the location of the 9 mark on a clock face)