English Dictionary

one o'clock

noun

(In both the 12-hour clock and the 24-hour clock) The start of the second hour of the day; 1:00 a.m. (01:00). / (Only in the 12-hour clock) The start of the fourteenth hour of the day; 1:00 p.m. (13:00).

It's already one o'clock.

意味（1）

(In both the 12-hour clock and the 24-hour clock) The start of the second hour of the day; 1:00 a.m. (01:00).

The bar closes at one o'clock (= The bar closes at 1:00 a.m.).

意味（2）

(Only in the 12-hour clock) The start of the fourteenth hour of the day; 1:00 p.m. (13:00).

The next train comes at one o'clock (= The next train comes at 13:00).

意味（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.

意味（4）

(informal) A dandelion.