1870, "public path beside a waterway," from French quai (12c., see quay). Often short for Quai d'Orsay, the street on the south bank of the Seine in Paris, since mid-19c. site of the French Ministry of Foreign Affairs and hence sometimes used metonymically for it (1922).
Examples from the Web for quai
The troops can consequently embark at Quai in about four hours.Operations Upon the Sea|Franz Edelsheim
You insisted on having our little apartment on the Quai Saint-Michel done up.The Widow Lerouge|Emile Gaboriau
We viewed the landscape—half of it was water and the little waves lapping against the quai were rather mocking.Lige on the Line of March|Glenna Lindsley Bigelow
Quai des Gesvres was built by the Marquis de Gesvres in 1641.Historic Paris|Jetta S. Wolff
When she reached the Quai de l'Horloge she slackened her steps, and felt refreshed by the cool breeze blowing from the Seine.The Fat and the Thin|Emile Zola