Metonymy, metaphor, synecdoche

clipped from en.wikipedia.org Metonymy and Synecdoche Synecdoche, where a specific part of something is taken to refer to the whole, is usually understood as a specific kind of metonymy. Sometimes, however, people make an absolute distinction between a metonymy and a synecdoche, treating metonymy as different from rather than inclusive of synecdoche. There is a similar problem with the usage of simile and metaphor. When the distinction is made, it is the following: when A is used to refer to B, it is a synecdoche if A is a part of B and a metonymy if A is commonly associated with B but not a part of it. An example of a single sentence that displays synecdoche, metaphor and metonymy would be: "Fifty keels ploughed the deep", where "keels" is the synecdoche as it takes a part (of the ship) as the whole (of the ship); "ploughed" is the metaphor as it substitutes the concept of ploughing a field for moving through the ocean; and "the deep" is the metonym, as "deepness" is an attribute associated with the ocean.