You can spice up your meal with chili powder — or you can spice up your room with a disco ball! Spice is usually a flavoring for food, but you can add spice to other things by jazzing them up.
Spices make your food more interesting and flavorful. Something that increases the excitement in other parts of life can also be called spice, like when the rivalry between two basketball players adds spice to the game. You can spice things up when you're telling a story by adding colorful details.