1Having many interrelated parts or aspects, so that it is not simple to understand, handle, or explain — complicated or intricate; also used for mixed, complex feelings.
この問題は複雑で、一度に全部を説明するのは難しい。
This issue is complicated; it's hard to explain everything at once.
彼の気持ちは複雑で、喜びと不安が入り混じっているようだ。
His feelings are complicated — it seems joy and anxiety are mixed together.
複雑な手続きのために、書類を何度も提出しなければならなかった。
Because the procedures were so complicated, I had to submit the documents several times.
家族の事情が複雑で、簡単には説明できない。
My family situation is complicated, so it's not easy to explain in short.