A coin of low denomination formerly used in Egypt and the Ottoman Empire: (originally) a silver half-dirham first issued in 1415 by the Mamluk Sultan al-Mu'ayyad Shaykh (at an initial weight of around 1.3 grams, but successively reduced in weight and silver content after the Ottoman conquest of Egypt in 1517); (later) a copper coin current in Egypt, Syria, etc., of approx. 6 grams, and valued at 1/40 of a piastre, or 1/20 of a penny, corresponding to the Turkish para.
In Egyptian Arabic it was commonly called faḍḍa, lit. ‘silver’ (Arabic fiḍḍa).
Late 16th century. From Middle French, French médin from colloquial Arabic maydī (perhaps via *meyyidī, variant of mu'ayyidī) from the name of al-Mu'ayyad Šayḵ, Mamluk Sultan of Egypt + -in.