What is vague?

This question is pretty vague.

For instance, does it mean "What is the definition of vague?" or does it mean "What sort of things are vague."

Vague is the adjective used to describe any answer given by a politician responding to a tough question.

In the fashion world it means out-of-date and, as such as the past tense of vogue.

Vague also describes this answer which you should not take seriously.