nutcracker
n. B1 Intermediate US //ˈnətˌkɹækɝ// UK //nˈʌtkɹækɐ// nut·crack·er
n. a tool or machine used to break open the hard shell of a nut. You use it to get the soft inside out without damaging it.
n. a tool or device designed to crack the shell of a nut or similar hard-shelled fruit.
I used a nutcracker to open the walnuts.
The kitchen drawer is full of various tools, including a nutcracker for opening pecans before baking.
While some people prefer to use their bare hands to crack a few nuts, a nutcracker provides a more efficient and less painful way to process large quantities for a recipe.
From nut + cracker.