What is an academic library?

Whilst meeting my mentor for my Cilip chartership we discussed the what my working role was and what is the role of an academic library and librarian?
Since then I have been thinking what is an academic library in the broadest sense? Via wikipedia it is:-

a library which serves an institution of higher learning, such as a college or a university — libraries in secondary and primary schools are called school libraries. These libraries serve two complementary purposes: to support the school's curriculum, and to support the research of the university faculty and students.

But every library has an individual approach to this. Where I work, te library is part of the University of London, and serves 22 London Universities. From tropical diseases to art. The academic library therefore has a large remit to cover. The mission statement of the library can be found here. The library therefore can at times be unwieldly with so many patrons to 'satisfy'. On top of this the Library is also being rewired, which means a three week closure, retraining and re-acquainting ourselves with re-opened area's.

I also feel academic libraries serve are what Tony Hirst recently wrote in a blog post:-

- students (i.e. people taking a course);

- lecturers (i.e. people creating or supporting a course);

- researchers;- folk off the web (i.e. people who Googled in who are none of the above).

Do we within an academic library fulfil our criteria for the 3 groups? I couldn't really discuss that here on my blog, but I do feel that things should be simplified for users. Anyhow, no more to add.