1. 直率的；不客气的；直言不讳的
    If you are blunt, you say exactly what you think without trying to be polite.

blunt的反义词

    e.g. She is blunt about her personal life...
           她对自己的私生活直言不讳。
    e.g. She told the industry in blunt terms that such discrimination is totally unacceptable.
           她直截了当地告诉业界，这种歧视是完全无法接受的。

2. （物体）钝的，不锋利的，不尖的
    A blunt object has a rounded or flat end rather than a sharp one.

    e.g. One of them had been struck 13 times over the head with a blunt object.
           他们中有一个人的头部被钝器击打13次。

3. （刀子或刀片）钝的，不锋利的
    A blunt knife or blade is no longer sharp and does not cut well.

4. 使（情感、感觉、需求）减弱；使迟钝
    If something blunts an emotion, a feeling or a need, it weakens it.

    e.g. The constant repetition of violence has blunted the human response to it...
           反复出现的暴力事件使人们的反应都变得麻木了。
    e.g. Our appetite was blunted by the beer.
           喝啤酒让我们没有了胃口。