Aggravate is a verb.
The meaning of aggravate is 'to make a difficult situation more serious or dangerous. Commonly the meaning of aggravate indicates making a situation worse.
'Making angry' is another meaning of aggravate.
Although aggravate is commonly used to mean annoy, but the meaning of aggravate is taken to be incorrect when in use by teachers.
So, the words Annoy and Angry are the synonyms of the word aggravate.
The following sentences make the meaning of aggravate more clear.
1. The lack of rain aggravated the already serious shortage of food.
2. Their debt problem further aggravated by the rise in interest rates.
3. Aggravating delays caused by heavy traffic need attention.
4. All difficulties are aggravated when you are there with me.