Someone who lunches, someone who eats lunch.(noun)
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Use "luncher" in a sentence
"Every Tuesday, he does a Q&A with a fellow Midtown luncher and today that Midtown luncher is yours truly."
"After his steak pie and roast potatoes, the luncher can take coffee in a solemn lounge where, at the press of a button, a huge vase will revolve slowly in its showcase."
"Any hungry luncher can eat 4 of those if no sides are included."