melodeon/mɪˈləʊdɪən/EtymologyFrom French mélodium, with change of ending.nounA type of reed organ with a single keyboard.“The thin, nearsighted young woman who had been humped over the keyboard of the melodeon, straightened up. The worshipers relaxed a little and began to look about.”An accordion where the melody-side keyboard is limited to the notes of diatonic scales in a small number of keys.“But Chae said it didn't matter, he'd bring his melodeon and Long Rob his fiddle; and faith! if that didn't content the folk they were looking for a church parade of the Gordons, not a wedding.”A music hall.