A dangerous aneurysm was found in his aorta during the checkup.

### 解释 aneurysm 是医学名词，指血管壁局部异常扩张形成的"动脉瘤"。这个词来自希腊语 aneurysma（扩张），由前缀 ana-（向上）和 eurys（宽）组成，描述血管壁向外膨出的病理状态。