Eat good food, especially to excess.
Late Middle English (as a noun): from French gourmandise, from gourmand ; the verb dates from the mid 16th century.
Gormandize entered English in the mid-1500s as a modification of gourmand, a term borrowed from the French that served as a synonym for glutton. The meanings of both gourmand and gormandize were clearly disparaging until the 19th century, when gourmet came into use to refer to a connoisseur of food and drink. Since then, the meaning of gourmand has softened, so that it now simply suggests someone who likes good food in large quantities. Gormandize still carries negative connotations of gluttony, but it can also imply that a big eater has a discriminating palate as well as a generous appetite.