hors d'oeuvre

noun3

1. •
   A small, light, and usually savory first course in a meal.
2. •
   Anything preliminary and of secondary concern.

   • His price was five hundred pounds in English or French gold—an interesting phase of your ordinary blackmailer's antipathy to paper—merely an hors d'oeuvre to the solid things to come, of course. — 1923
3. •
   (old-fashioned, rare) Something unusual or extraordinary.