What is "to exacebrate?

I'm reading a book and seeing the inflected verb exacebrated and wondered what it means.
Answers.com says:

To increase the severity, violence, or bitterness of; aggravate: a speech that exacerbated racial tensions; a heavy rainfall that exacerbated the flood problems.

Let's see some examples of using this verb in a sentence:

Global Warming to Exacerbate China's Water Crisis

or

Smoking may exacerbate the increased risk of a blood vessel bursting inside the brain (intracerebral stroke) already faced by people with high blood pressure

So we see that its meaning is to make things worse and move severe.