further: [OE] Etymologically, further is simply a comparative form of forth, and originally meant nothing more than simply ‘more forward’. Its more metaphorical senses, ‘in addition’ and ‘to a greater extent’, are secondary developments. It was formed in the pre-historic Germanic period, and so has relatives in other Germanic languages, such as German vorder. Its verbal use is apparently equally ancient. => forth[further etymology, further origin, 英语词源]