Definition of "mustache"

“My Continental prominence is improving,” I commented dryly. ¶ Von Lindowe cut at a furze bush with his silver-mounted rattan. ¶ “Quite so,” he said as dryly, his hand at his mustache. “I may say if your intentions were known your life would not be worth a curse.”

1908, W[illiam] B[lair] M[orton] Ferguson, “Zollenstein”, in Zollenstein, New York, N.Y.: D. Appleton & Company, page 41