Meaning
To go to bed or go to sleep.
It’s casual and often said at the end of a long day, sometimes with a note of relief or tiredness.
Origin
The underlying image is old: for centuries, ordinary mattresses across many cultures, including ancient Egypt, were simple sacks stuffed with straw, hay, or grass, so lying down for sleep literally meant getting into a sack. The related phrase “hit the hay” is documented earlier, appearing in English by the early 1900s, while “hit the sack” specifically is most solidly documented from the World War II era — a 1944 wartime journal by U.S. Navy sailor Thomas D. Schreck records: “Got the ship slowed down because of a sub warning. Hit the sack at 21:00,” reflecting military slang possibly influenced by soldiers’ canvas sleeping bags rather than straw mattresses directly. So while the straw-sack sleeping surface itself is ancient, the specific fixed phrase “hit the sack” is a comparatively modern, mid-20th-century American development.
Examples
I’m exhausted, I’m going to hit the sack.
He hit the sack right after dinner.
It’s midnight, we should hit the sack.
A: “Are you staying up?” B: “No, I’m about to hit the sack.”
Frequently asked questions
What does 'Hit the sack' mean?
To go to bed or go to sleep.
It’s casual and often said at the end of a long day, sometimes with a note of relief or tiredness.