pilón
/ˈpɪlɒn/(also pelon, pilon, pilone) United States regional (chiefly south-western )
noun
In Mexico and the south-western United States: a small gift given to a customer who is making a purchase or settling an account; the action of giving such a gift.
Origin
Late 19th century; earliest use found in Harper's Magazine. FromMexican Spanish pilón (probably 1816), specifically sense of Spanish pilón sugar-loaf (more fully pilón de azúcar; so called on account of its conical shape) from pila + -on.