desert island

Meanings

1. A deserted island, an uninhabited island, especially one in the tropics and (now frequently misunderstood as) a small and almost entirely sandy desert.
2. An island that is completely or mostly a desert, an arid island.
3. Describing a thing considered so personally indispensable or beloved that one could never tire of it, used especially for books and music.

Etymology

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 alone on an island.