Definition of "leading light" []

• An acclaimed expert, one of the foremost experts, a luminary. (noun)

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• "Here we met Simon Fairlie, leading light of the experiment from the beginning, eloquent veteran of the Twyford Down road protest, sometime Associate Editor of the Ecologist and once a stonemason at Salisbury Cathedral."
• "He was not yet a leading light in the underworld, but he was already too big a man to soil his hands in fights in the bars of the Vieux Port."
• "D., a leading light of the Methodist Episcopal Church, who offers himself as comic relief in our Clerical Vaudeville."