complication
/ˌkɒmplɪˈkeɪʃən/noun
1
- a circumstance that complicates something; a difficulty使复杂化的情况; 困难, 难题：
there is a complication concerning ownership of the site.
关于这个地点的所有权存在着一个难题。
1.1
- mass noun an involved or confused condition or state复杂（情况）; 混乱：
to add further complication, English-speakers use a different name.
使情况更加复杂化的是说英语的人使用的是一个不同的名称。
2
- Medicine a secondary disease or condition aggravating an already existing one【医】并发症：
she developed complications after the surgery.
外科手术后, 她患了并发症。
词源
late Middle English: from late Latin complicatio（n-）， from Latin complicare 'fold together' （see COMPLICATE）.