1. 更新；使现代化
    If you update something, you make it more modern, usually by adding new parts to it or giving new information.

    e.g. He was back in the office, updating the work schedule on the computer...
           他已回到办公室，正在电脑上更新工作日程。
    e.g. Airlines would prefer to update rather than retrain crews.
           航空公司更愿意换新员工而不是对旧员工重新进行培训。

2. 最新消息；快讯；速递
    An update is a news item containing the latest information about a particular situation.

    e.g. She had heard the news-flash on a TV channel's news update.
           她在一家电视台的新闻快讯中听到了这则简明新闻。
    e.g. ...a weather update.
           最新天气报告

3. 为…提供最新消息；把最新进展告诉（某人）
    If you update someone on a situation, you tell them the latest developments in that situation.

    e.g. We'll update you on the day's top news stories...
           我们将为您提供当天的重要新闻。
    e.g. I would just update them on any news we might have.
           我们一有新消息我就会告诉他们。