The word for ‘orange’ in most European languages ultimately comes from the Sanskrit नारङ्ग ‹nāraṅga›. This was borrowed into Persian as نارنگ ‹nârang›, which in turn was entered into Arabic as نارنج ‹nāranj›. Spanish and Portuguese borrowed this word from Arabic with minimal modification as ‹naranja› and ‹laranja›, respectively. The English form “orange” comes from Old Provençal ‹auranja› via Old French ‹orenge›. The dropping of the initial n in these latter examples is most likely a result of rebracketing, in which a phrase like ‹une norenge› was interpreted by speakers as ‹une orenge›.
Despite such historical influence, Arabic ‹nāranj› has become obsolete in the modern language, and the current word is برتقال ‹burtuqāl›, which is a medieval transliteration of “Portugal.” A number of other languages also derive their word for ‘orange’ from the name Portugal. Examples include Albanian ‹portokall›, Amharic ብርቱካን ‹bərtukan›, Georgian ფორთოხალი ‹p’ort’oxali›, Greek πορτοκάλι ‹portokáli›, Kurdish پرتهقاڵ ‹pirteqal›, Neapolitan ‹purtuallo›, Persian پرتقال ‹porteqāl›, and Turkish ‹portakal›.
The reason for this intriguing quirk is that Portugal was once the largest exporter of oranges in the Mediterranean. The fruit became so associated with the country that it took on its name in virtually all the languages spoken in the wider region.
In a way, the spread of this name is a medieval-era meme. It demonstrates how ideas (for example, the association of orange and Portugal) migrate through language itself.