Giffard Grenade (pomegranate) liqueur is one of the classic liqueur expressions. It presents a bright red flavored with pomegranate extract. They call the taste "fruity and astringent."
Giffard is a French company specializing in a wide variety of liqueurs and eua-de-vie among other products. Some of those extra products are flavored cocktail syrups (or "sirop"). They are generally sweetened with pure cane sugar.