four o'clock

noun5

1. •
   The start of the fifth hour of the day; 4:00 a.m. (04:00).

   • The breakfast buffet opens at four o'clock (= "The breakfast buffet opens at 4:00 a.m.").
2. •
   The start of the seventeenth hour of the day; 4:00 p.m. (16:00).

   • The next train comes at four o'clock (= "The next train comes at 16:00").
3. •
   (informal) A position to the right and slightly behind (horizontal clock orientation) (from the location of the 4 mark on a clock face)

   • We've got a bogey at four o'clock.
4. •
   Any of several plants, of the genus Mirabilis, whose funnel-shaped flowers open in late afternoon.
5. •
   The friarbirds (Philemon spp.); so called from its cry, which resembles these words.