difficult to detect or grasp by the mind or analyze; "his whole attitude had undergone a subtle change"; "a subtle difference"; "that elusive thing the soul"心または分析により検出する、あるいは把握することが難しい微妙
例:that elusive thing the soul そのとらえどころのないものである精神
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難解