If you crack a joke, you tell it. He cracked jokes and talked about beer and girls. see also cracked, cracking
If your voice cracks when you are speaking or singing, it changes in pitch because you are feeling a strong emotion. Her voice cracked and she began to cry
If someone cracks, they lose control of their emotions or actions because they are under a lot of pressure. She's calm and strong, and she is just not going to crack
If you say that something is not all it's cracked up to be, you mean that it is not as good as other people have said it is. Package holidays are not always all they're cracked up to be
If you crack a hard part of your body, such as your knee or your head, you hurt it by accidentally hitting it hard against something. He cracked his head on the pavement and was knocked cold. = bang, bash
When you crack something that has a shell, such as an egg or a nut, you break the shell in order to reach the inside part. Crack the eggs into a bowl. = break
If something hard cracks, or if you crack it, it becomes slightly damaged, with lines appearing on its surface. A gas main had cracked under my neighbour's garage and gas had seeped into our homes Remove the dish from the oven, crack the salt crust and you will find the skin just peels off the fish
If something cracks, or if you crack it, it makes a sharp sound like the sound of a piece of wood breaking. Thunder cracked in the sky He cracked his fingers nervously
If you crack a problem or a code, you solve it, especially after a lot of thought. He has finally cracked the system after years of painstaking research