It seems that, although u3a was coined as an acronym for University of the Third Age, the ‘university’ word carried too many implications. What follows is a more accurate description gleaned from the Hillingdon u3a website:

Based in West London, Hillingdon u3a provides many educational, creative and leisure opportunities for its members in a friendly environment. This is achieved by its members running over 80 interest groups. You can see the list of these in the Groups page. Hillingdon u3a is well established having formed 24 years ago and now has over 850 members across the Ruislip, Ickenham, Uxbridge, Hillingdon, Hayes and West Drayton area. It also has an active social programme of monthly meetings, visits, walks, concerts, theatre trips and a regular members’ newsletter.