Variant spelling of Geoffrey, common in the Middle Ages (as reflected in surnames such as Jefferson). This is now the usual spelling of the name both in North America and Britain. Well-known bearers include the novelist and former British politician Jeffrey Archer (b. 1940), the British conductor Jeffrey Tate (b. 1943), and the American soul singer Jeffrey Osborne (b. 1951).
English: from Middle English more ‘moor’, ‘marsh’, ‘fen’, ‘area of uncultivated land’ (Old English mōr), hence a topographic name for someone who lived in such a place or a habitational name from any of the various places named with this word, as for example Moore in Cheshire or More in Shropshire.