desert island

From the former sense of desert to mean deserted (“uninhabited”), particularly common on Spanish and Portuguese maps during the Age of Exploration as isla desierta, ilha deserta, and Medieval Latin isla deserta (“uninhabited island”). Now frequently misunderstood as simply desert (“dry, arid location”) and imagined as almost entirely sandy.

As an indispensable thing, from the idea of loving something to the point one would want it on a deserted island where it would be used ad infinitum but never ad nauseam. Popularized by the radio show Desert Island Discs (first broadcast 1942) which asked guests what they would take with them if marooned