(In both the 12-hour clock and the 24-hour clock) The start of the fifth hour of the day; 4:00 a.m. (04:00). / (Only in the 12-hour clock) The start of the seventeenth hour of the day; 4:00 p.m. (16:00).

(In both the 12-hour clock and the 24-hour clock) The start of the ninth hour of the day; 8:00 a.m. (08:00).

(In both the 12-hour clock and the 24-hour clock) 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 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).

(In both the 12-hour clock and the 24-hour clock) The start of the eleventh hour of the day; 10:00 a.m. (10:00).

(In both the 12-hour clock and the 24-hour clock) The start of the seventh hour of the day; 6:00 a.m. (06:00).

(US, especially black slang, of a woman) Straight up and down, without curves, like the hands of a clock.

(In both the 12-hour clock and the 24-hour clock) The start of the eighth hour of the day; 7:00 a.m. (07:00). / (Only in the 12-hour clock) The start of the twentieth hour of the day; 7:00 p.m. (19:00).

(In both the 12-hour clock and the 24-hour clock) The start of the fourth hour of the day; 3:00 a.m. (03:00). / (Only in the 12-hour clock) The start of the sixteenth hour of the day; 3:00 p.m. (15:00).

(informal, humorous) A time of day, usually during the night or early in the morning, considered unreasonable or when one is prone to poor judgment.