1. 脆的；易碎的
    An object or substance that is brittle is hard but easily broken.

    e.g. Pine is brittle and breaks.
           松树很脆，容易折断。
    e.g. ...the dry, brittle ends of the hair.
           又干又脆的发梢

2. 脆弱的；不稳固的；易变的
    If you describe a situation, relationship, or someone's mood as brittle, you mean that it is unstable, and may easily change.

    e.g. These incidents suggest the peace in Northern Ireland is still brittle...
           这些事件表明北爱尔兰的和平仍然很脆弱。
    e.g. This may help to undermine the brittle truce that currently exists.
           这也许会火上浇油，破坏当前脆弱不稳的休战局面。

3. 尖刻的；冷漠麻木的
    Someone who is brittle seems rather sharp and insensitive and says things which are likely to hurt other people's feelings.

brittle

    e.g. ...Noel Coward's brittle comedy of bad manners.
           诺埃尔·科沃德尖锐嘲讽无礼举止的喜剧

4. （声音）尖厉的
    A brittle sound is short, loud, and sharp.

    e.g. Myrtle gave a brittle laugh.
           默特尔冷笑了一声。