Lagniappe

A lagniappe (/ˈlænjæp/ LAN-yap) is a small gift given to a customer by a merchant at the time of a purchase (such as a 13th doughnut when buying a dozen), or more broadly, "something given or obtained gratuitously or by way of good measure."

The word entered English from the Louisiana French adapting a Quechua word brought in to New Orleans by the Spanish Creoles. It derived from the South American Spanish phrase la yapa or ñapa (referring to a free extra item, usually a very cheap one). La is the definite article in Spanish as well as in French (la ñapa or la gniappe = the ñapa/gniappe). The term has been traced back to the Quechua word yapay ('to increase; to add'). In Andean markets it is still customary to ask for a yapa (translates as "a little extra") when making a purchase. The seller usually responds by throwing in a little extra.