Definition of "Monsieur"

It will appear by the Minutes sent You to June i6th last, and by those which accompany this Letter, that Messieurs Smith and Schlatter have done their Part; [...]

1880, Horace Wemyss Smith, Life and Correspondence of the Rev. William Smith, D. D.: First Provost of the College and Academy of Philadelphia. First President of Washington College, Maryland. With Copious Extracts from His Writings, page 140

As the Monsieurs suddenly showed up and confronted the situation with wicked grins on their faces, the gang members decided to sullenly disperse and slink away. It was like a scene from an old West showdown.

2011, Rick Johnson, That's My Teenage Son: How Moms Can Influence Their Boys to Become Good Men, Revell, page 204

Estella smiled when she considered how very different her circumstances were now to those when, not so long ago, she had feared Monsieur Jones, and thought of him only as her captor. Now, he was something else: her liberator, ...

2014, Tasha Alexander, The Counterfeit Heiress: A Lady Emily Mystery, Minotaur Books, page 244