| 难题 | [难 题 / 難 題] difficult problem #4,588 [Add to Longdo] |
| 難題 | [なんだい, nandai] (n) difficult problem; challenge; (P) [Add to Longdo] |
| 難問 | [なんもん, nanmon] (n, vs) perplexity; difficult question; difficult problem; (P) [Add to Longdo] |
| 難問山積 | [なんもんさんせき, nanmonsanseki] (n) mountain (pile) of difficult problems [Add to Longdo] |
| 難問題 | [なんもんだい, nanmondai] (n) difficult problem or question [Add to Longdo] |