じゅうのしま【十の島・十のしま】 : juu no shima | define meaning

Attested since the Edo period. The term is an orthographical play on the popular word あほ aho "idiot": the characters 十 juu and の no would combine to form the shape of the character あ a, while し shi and ま ma would combine to form the character ほ ho. These last two are then respelled with the kanji for "island", 島 shima, thus giving 十の島 juu no shima (literally "ten islands").