1. 极度的；最大的
    You can use utmost to emphasize the importance or seriousness of something or to emphasize the way that it is done.

    e.g. It is a matter of the utmost urgency to find out what has happened to these people...
           当务之急是要弄清楚这些人出了什么事。
    e.g. Security matters are treated with the utmost seriousness...
           安全问题的处理极其严肃。

2. 极度；极限；最大可能
    If you say that you are doing your utmost to do something, you are emphasizing that you are trying as hard as you can to do it.

utmost什么意思

    e.g. He would have done his utmost to help her, of that she was certain...
           他肯定会尽最大努力帮她，这一点她非常肯定。
    e.g. He will try his utmost to help them by means of his conventional medical knowledge.
           他将会用自己的传统医学知识尽全力帮助他们。

3. 尽力；极度
    If you say that something is done to the utmost, you are emphasizing that it is done to the greatest extent, amount, or degree possible.

    e.g. My limited diplomatic skills were tested to the utmost...
           我有限的外交手腕儿受到了极其严峻的考验。
    e.g. The best plan is to continue to attack him to the utmost of our power.
           最佳方案就是继续不遗余力地攻击他。