1. 可能；可能性
    The likelihood of something happening is how likely it is to happen.

    e.g. The likelihood of infection is minimal...
           感染的可能性极小。
    e.g. There didn't seem much likelihood of it happening...
           这种事情发生的可能性不大。

2. 可能的事
    If something is a likelihood, it is likely to happen.

    e.g. But the likelihood is that people would be willing to pay if they were certain that their money was going to a good cause...
           但如果人们确切知道自己的钱会用于做善事，他们就可能更愿意掏腰包。
    e.g. That, as we all know, is not only a possibility but a likelihood.
           众所周知，那不仅可能发生，而且是很可能发生。

3. 十之八九；极有可能
    If you say that something will happen in all likelihood, you mean that it will probably happen.

    e.g. In all likelihood, the committee will have to interview every woman who's worked with Thomas.
           十有八九，委员会将不得不与每一位曾和托马斯共过事的女性面谈。