An amuse-bouche is a single, bite-sized hors d’œuvre.
Amuse-bouches are different from appetizers in that they are not ordered from a menu by patrons, but, when served, are done so according to the chef's selection alone. These, often accompanied by a complementing wine, are served as a little tingler for the taste buds both to prepare the guest for the meal and to offer a glimpse into the chef's approach to cooking.
The term is French, literally translated to "mouth amuser".