Lost Colony a name for the first English settlement in America, birthplace of Virginia Dare, which was established on Roanoke Island in 1585 and had mysteriously disappeared by 1591.
lost generation the generation reaching maturity during and just after the First World War, a high proportion of whose men were killed during those years. The expression was applied by Gertrude Stein to disillusioned young American writers who went to live in Paris in the 1920s.
Lost Leader from the title of a poem by Robert Browning (1845) on Wordsworth's acceptance of the office of Poet Laureate, condemning the poet's abandonment of radical principles with the lines, ‘Just for a handful of silver he left us, just for a riband to stick in his coat’.
Lost Tribes of Israel the ten tribes of Israel taken away c.720 bc to captivity in Assyria (2 Kings 17:6), from which they are believed never to have returned, while the tribes of Benjamin and Judah remained.
See also for want of a nail the shoe was lost at want1.