Kuruş, also gurush, ersh, gersh, grush, grosha, and grosi, are all names for currency denominations in and around the territories formerly part of the Ottoman Empire. The variation in the name stems from the different languages it is used in and the different transcriptions into the Latin alphabet. In European languages, the kuruş was known as the piastre.

The piastre or piaster is any of a number of units of currency. The term originates from the Italian for "thin metal plate". The name was applied to Spanish and Hispanic American pieces of eight, or pesos, by Venetian traders in the Levant in the 16th century.