Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
involving people or organizations that choose to take part in an activity, rather than being chosen by someone else:
Share your knowledge with the community
Browse our collection of 300,000+ community-written definitions
