AYR, a river in the parish of Muirkirk, in Ayrshire; which after a course of about eighteen miles nearly due west falls into the sea at Ayr, where its salutary forms a fine harbour. It is for a considerable course only a small rivulet; but joined by the Greenock and Garpel, tributary streams, it becomes a large body of water. It frequently shifts its bed, and does considerable damage by its encroachments. Its banks are steep and very romantic; and the number of seats which ornament them present a fine picturesque scenery. Sorn-castle, Auchincruive, and Auchinleck, may be mentioned as the chief beauties of the scene. The village of Catrine is situated on its banks. It forms the boundary between the districts of Ayrshire, denominated Kyle and Carrick.