piece of eight

plural pieces of eight

1. historicalThe peso, a silver coin that was minted in Spain and its colonies from the end of 15th century, equal to eight reales (hence the name).

   It was a long, difficult business, for the coins were of all countries and sizes — doubloons, and louis d'ors, and guineas, and pieces of eight, and I know not what besides, all shaken together at random.

   1881–1882, Robert Louis Stevenson, Treasure Island, London; Paris: Cassell & Company, published 14 November 1883, →OCLC

   Synonyms: dollar, peso, piastre