1 文書を見つけるための辞書。

• problematical, elusive, tough, problematic, knotty, baffling
• 複雑, 捕らえ所のない, 苦しい, ハード, 捉え所の無い, 捕らえ所の無い, 困難, 捉え所のない, 難解, 手ごわい, 手強い
• making great mental demands; hard to comprehend or solve or believe; "a baffling problem"; "I faced the knotty problem of what to have for breakfast"; "a problematic situation at home"
• 大きな精神的な要求を行うさま