Old English sweart "black, dark," of night, clouds, also figurative, "wicked, infamous," from Proto-Germanic *swarta- (cognates: Old Frisian, Old Saxon, and Middle Dutch swart, Dutch zwart, Old Norse svartr, German schwarz, Gothic swarts "dark-colored, black"), from PIE root *swordo- "dirty, dark, black" (source of sordid). The true Germanic word, surviving in the Continental languages, displaced in English by black. Of skin color of persons from late 14c. Related: Swartest.