I think no one knows how or why "raining cats and dogs" came to be. It just means heavy, hard rain. Perhaps as if the drops of water are big and hit hard, as if they're the size of small animals?
"Sack" is a euphemism for bed. The bed linens are like a sack or bag. We call it a "sleeping bag". When you crawl under the blankets, it makes a cozysack for your body.
"Bouncing off the walls" means out of control, bouncing around without reason or purpose.
1. It's raining cats and dogs.
2. Hit the sack.
3. You're bouncing off the walls.
What is the inferential meaning of all the 3 idioms?
2 answers
What, like Scooby-Doo in that movie with dinosaurs?
1 answer