leading light definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
an important or influential member of a club, community, etc.
leading light - Phrases/Idioms
An important or influential individual, as in Jim was a leading light in his community. This expression, alluding to moral guidance, dates from about 1870, but terms such as a shining light have been used for an outstanding person since the first half of the 1500s.