A strath is a large valley, typically a river valley that is wide and shallow (as opposed to a glen, which is typically narrower and deep).
An anglicisation of the Gaelic word srath, it is one of many that have been absorbed into the English language. It is commonly used in rural Scotland to describe a wide valley, even by non-Gaelic speakers.
It occurs in numerous place names within Scotland including Strathspey and Strathclyde. Internationally, many places with Scottish heritage also use the prefix including Strath-Taieri in New Zealand; Strathfield, a suburb of Sydney, Australia; Strathewen, Victoria, Australia; Strathpine, a suburb of Brisbane, Australia; and various places in Canada: Strathmore, Alberta; ; Strathroy, Ontario; and Strathburn, Ontario.
It also occurs in the names of five Peninsular and Oriental Steam Navigation Company liners, four of which, the Strathaird, the Strathnaver, the Stratheden and the Strathmore carried thousands of migrants to Australia between the 1950s and the 1960s. The ships acted as troop carriers during the Second World War and the fifth ship, the Strathallan, sank in the Mediterranean in 1942 taking troops to the landings in North Africa.