1.
difficult problem; tough question; hard challenge
A problem or question that is very hard to solve or answer. Used for academic questions, puzzles, and also figuratively for real-world challenges.
この難問が解けない。
I can't solve this difficult problem.
試験に難問が多くて苦戦した。
I struggled because there were many difficult questions on the exam.
少子化は日本が直面している難問のひとつだ。
The declining birth rate is one of the tough challenges facing Japan.
難問 covers both academic test questions and real-world challenges that are hard to resolve.
COMMON COLLOCATIONS:
- 難問に挑む: to tackle a tough problem
- 難問を解く: to solve a difficult problem
- 難問を解決する: to resolve a difficult problem
- 難問奇問: bizarre and difficult questions (used for exams with unfairly tricky questions)
- 難問に直面する: to face a difficult problem
SIMILAR WORDS:
- 難題: difficult task or unreasonable demand (leans toward 'tall order')
- 問題: problem/question (general, neutral difficulty)
- 難問 specifically emphasizes difficulty