1. Meaning "little toasts" in Italian, crostini are small, thin slices of toasted bread, which are usually brushed with olive oil. 2. The word also describes canapéS consisting of small slices of toast with a savory topping such as cheese, shrimp, pâté or anchovies. 3. Sometimes crostini refers to the equivalent of a crouton used for soups or salads.