Other way around - synecdoche usually refers to a whole through a part (calling an entire ship by just saying stern, for example) but a part through a whole is

Other way around - synecdoche usually refers to a whole through a part (calling an entire ship by just saying stern, for example) but a part through a whole is usually called metonymy. Synecdoche is a subset of metonymy. Edit: the wikipedia article does mention that it can be a part through a whole. But this is at odds with my Classical background.