14th cent. The adjectival sense was a semantic extension of the fruit. From Arabic nāranj "orange," borrowed from Persian nārang 'id.,' itself borrowed from Sanskrit nāraṅga "orange tree."
Of unknown origin.
Also the origin of Naranjo and Naranco, two mountain areas in Oviedo, probably so-called to reference their orange color. Also the mountain peakNaranjo/Naranco de Bulnes, a mountain peak in Asturias named by German geologist Wilhelm Schulz in 1855, probably based on its orange color (its original name is Picu Urriellu).
Romance: Western Vulgar Latin: Asturian naranxa, (Fernán Coronas) llaranxa, Portuguese laranja, Catalan taronja