dark: [OE] Dark comes ultimately from a Germanic base *derk-, *dark-, which also produced Old High German tarchanjan ‘hide’ and Middle Low German dork ‘place where dirt collects’ (outside Germanic, Lithuanian dargus has been compared). In Old English the word usually denoted absence of light, particularly with reference to ‘night’; the application to colours did not develop until the 16th century. [dark etymology, dark origin, 英语词源]