Samurai were the military nobility of pre-industrial Japan. According to translator William Scott Wilson: 'In Chinese, the character was originally a verb meaning to wait upon or accompany persons in the upper ranks of society, and this is also true of the original term in Japanese, saburau. In both countries the terms were nominalized to mean 'those who serve in close attendance to the nobility,' the pronunciation in Japanese changing to saburai. According to Wilson, an early reference to the word 'samurai' appears in the Kokin Wakash (905-914), the first imperial anthology of poems, completed in the first part of the 10th century. By the end of the 12th century, samurai became almost entirely synonymous with bushi , and the word was closely associated with the middle and upper echelons of the warrior class. The samurai followed a set of rules that came to be known as bushid.
Contributions by Revth, 18.104.22.168, and Tbjablin.