the light and heat that come from the sun

The children were out playing in the sunshine. 孩子们正在外面太阳下玩耍。

happiness or pleasure

Their grandchildren have brought sunshine into their lives. 他们的孙辈给他们的生活带来了快乐。

used as a form of address, either in a friendly way, or to express unwillingness to accept another person's delays, bad behaviour, etc.

Hello, sunshine! 你好，亲爱的！

Come on, sunshine, get to work. 快点儿，亲爱的，开始干活吧。