So I'm really sorry. But when you use a part of something -- like the dictionary is a part of the language, or a flag stands for the United States, it's a symbol of the country -- then you're using it synecdochically.
Stoga, jako mi je žao. Kada koristite dio nečega -- kao rječnik koji je dio jezika, ili zastavu koja predstavlja SAD, simbol države – tada to koristite sinegdotski.