A Renfrewshire seaport on the S. shore of the Firth of Clyde, 3 m. E. of Greenock and 20 W. of Glasgow; was founded by the magistrates of Glasgow in 1668 as a port for that city before the deepening of the river was projected. In the beginning of the 18th century it was the chief port on the Clyde, but has since been surpassed by Greenock and Glasgow itself. There are shipbuilding, iron and brass founding industries, and extensive timber ponds.