Sound, n. [AS. sund a narrow sea or strait; akin to Icel., Sw., Dan. & G. sund, probably so named because it could be swum across. See Swim.] (Geog.) A narrow passage of water, or a strait between the mainland and an island; also, a strait connecting two seas, or connecting a sea or lake with the ocean; as, the Sound between the Baltic and the german Ocean; Long Island Sound.
The Sound of Denmark, where ships pay toll. Camden.
Sound dues, tolls formerly imposed by Denmark on vessels passing through the Baltic Sound.