1. 谜;谜语
    A riddle is a puzzle or joke in which you ask a question that seems to be nonsense but which has a clever or amusing answer.

2. 谜团;费解的事
    You can describe something as a riddle if people have been trying to understand or explain it but have not been able to.

    e.g. Scientists claimed yesterday to have solved the riddle of the birth of the Universe.
           科学家们昨天声称已经解开了宇宙形成之谜。

3. （用子弹）把…打得到处是洞，使满是弹孔
    If someone riddles something with bullets or bullet holes, they fire a lot of bullets into it.

    e.g. Unknown attackers riddled two homes with gunfire...
           来路不明的袭击者用枪炮将两处住宅打得千疮百孔。
    e.g. The darkness saved me from being riddled with bullets.
           身处黑暗中让我不至于被子弹打得浑身是洞。