what exactly is an amuse bouche?

I love Claridges.  There is always such a sense of occasion and both the service and the quality of food are second to none.  I was in the Foyer restaurant  and they served this parmesan gnocchi as an amuse bouche!  I love this term.  It literally means mouth happiness and this is exactly was I got!  Sometimes, Gnocchi can be very heavy and can feel quite doughy in the mouth!.  This was literally melt in the mouth, light and delicious