Meaning: A difficult problem to solve, a challenging situation to handle, or a person who is hard to understand or convince.
Usage in Example Sentences:
- “Convincing him to join the team will be a tough nut to crack—he’s very stubborn.”
- “This math problem is a tough nut to crack; I’ve been working on it for hours.”
- “She’s a tough nut to crack, but once you get to know her, she’s really friendly.”
Origin:
The phrase comes from the literal difficulty of cracking certain types of nuts with a hard shell, like walnuts or pecans. It has been used metaphorically since the 1800s to describe situations or people that require effort and persistence to overcome or understand.