n. Chiefly Southern Louisiana & Mississippi.
1. A small gift presented by a storeowner to a customer with the customer's purchase.
2. An extra or unexpected gift or benefit.
Lagniappe derives from New World Spanish la ńapa, “the gift,” and ultimately from Quechua yapay, “to give more.” The word came into the rich Creole dialect mixture of New Orleans and there acquired a French spelling.
It is still used in the Gulf states, especially southern Louisiana, to denote a little bonus that a friendly shopkeeper might add to a purchase. By extension, it may mean “an extra or unexpected gift or benefit.”