From Latin 'insula' (island) — the Latinate word, used in literary contexts, distinct from Germanic 'island.'
An island, especially a small one. Used chiefly in literary or poetic contexts and in proper names.
From Old French isle (island), from Latin insula (island), of uncertain ultimate etymology — possibly from PIE *h₁en- (in) + *sal- (sea, salt water), meaning literally in-the-sea, or alternatively from an Etruscan or Mediterranean substrate root. The Latin insula also gave insular (island-like, isolated), insulate (to make into an island), peninsula (almost-island, from paene, almost), and the Insula Tiberina in Rome. The French isle dropped its internal s by the medieval period (giving modern French île), but English spelling
The word 'island' is NOT derived from 'isle,' despite their similar spellings and meanings. 'Island' comes from Old English 'īegland' (water-land), a purely Germanic word. The 's' was inserted into 'island' in the fifteenth century by scribes who incorrectly assumed it was related to 'isle' and Latin 'insula.' The silent 's' in 'island' is thus a spelling error that became permanent — a ghost letter born