1. I’m really tired—I can’t keep my eyes open any longer. I’m going to hit the sack.
2. After a hard day, Richard decided to hit the sack even though it was only 8:00 p.m.
22. IN THE PINK in good health or good condition
After several days in the hospital, Paul wanted to go home. He told the doctor he was feeling in the pink and there was no reason for him to stay any longer.
I always get my car serviced on time. That way it stays in the pink and I don’t have to worry about it breaking down.
Antonym: under the weather In the pink can be applied to both people and things, while under the weather is limited to people. The expression probably originates from the idea that a healthy person’s complexion is described as pink, while a sick person’s skin is pale or chalky.