Difference between lunch and luncheon?

Hi, what exactly is the difference between lunch and luncheon? Is a luncheon a more formal event like a business meeting over lunch? Is luncheon an American term? Thank you for your answers.

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Both British and American dictionaries list luncheon as a formal variety of lunch– a fancier midday meal, often in celebration, for business or for guests. The American Heritage Dictionary also calls it an afternoon party including a light meal, so it may have a broader connotation in AmE.
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Hello Mister Micawber,

So is it safe to say that you would invite your girl friend or wife to lunch and a client or business partner to a luncheon?

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Oh, either one is ‘safe’, I think. Unless it is fancy and recreational rather than for the purpose of transacting business, I would call most business ones business lunch.
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