Input: What does the abbreviation AIDS stand for ?

What kind of thing would answer this question?
***
Output: abbreviation


Input: What is the high pitched sound that you hear in your ear every now and then , but then it goes away , after a while ?

What kind of thing would answer this question?
***
Output: entity


Input: What is chronic constipation a symptom of ?

What kind of thing would answer this question?
***
Output:
entity