To be enigmatic or mysterious; to have an air of puzzlement or secrecy about someone or something.
彼の微笑にはどこか謎めくものがあって、誰も本心を読めなかった。
There was something enigmatic about his smile, and no one could read his true feelings.
古い日記を読むと、その作者の人生が謎めいて見える。
Reading the old diary makes the author's life seem mysterious.
事件の結末が謎めいているため、読者の想像力を刺激する作品だ。
Because the ending of the case is enigmatic, it is a work that stimulates the reader's imagination.