| An appetizer is the first part of a meal, designed to boost the appetite of the diner. It tends to be a small amount of food. The idea is that this stimulates the mouth to produce saliva and the stomach to produce acid ready for the arrival of food in the main course. These reactions in the body make a person feel physically ready to eat, but the flavour in the appetizer also stimulates the mind and inspires the correct mood for tucking into some delicious food. It provides a taste of what is to come.
The term is also sometimes used to refer to anything that provides people with a suggestion of something good on it's way. A preview of a film may be called an appetizer or mild flirtation on a date may be considered an appetizer, rasing anticipation of activities to come.
This is one of those words that we spell differently in British English, as appetiser. | 
