(US, slang, street slang) The police.

(In both the 12-hour clock and the 24-hour clock) The start of the sixth hour of the day; 5:00 a.m. (05:00). / (Only in the 12-hour clock) The start of the eighteenth hour of the day; 5:00 p.m. (17:00).

A beard growth visible late in the day on the face of a person with facial hair growth that was clean-shaven in the morning.

plural of five o'clock shadow

(card games) five cards of the same rank, often only possible if one or more wild cards are being used.

Alternative form of five of a kind

(idiomatic) Used as an excuse for drinking alcoholic beverages outside of customary hours.