An hors d'oeuvre [pronounced ‘or-DURV'] is a small savory dish that is served before a main meal.
Hors d'oeuvres may be served at the table as part of the sit-down meal or may be served before guests are seated at the table. Passed hors d'oeuvres are a popular way to serve food during the cocktail reception.
The word hors d'oeuvre is French and literally means “outside the work”.
The term appetizer can be used interchangeably with the word hors d'oeuvre (plus it's sooo much easier to spell!)