Metonymy is a thing or concept that isn't called by its own name, but by the name of something intimately associated with it.
http://en.wikipedia.org/wiki/Metonymy
-Metonymy is used as a figure of speech or as a replacement word.
Example: "The mighty hand leads to a sloping shoulder,
The finger joints are cramped with chalk;
A gooses quill has put an end to murder
That put an end to talk."
*In this poem The Hand That Signed the Paper, Thomas critisizes the ruler and the amount of power associated with rulers and people of high power. The "gooses quill" mentioned in the poem is a metonymy that refers to power that is associated with the ruler's hand.
http://en.wikipedia.org/wiki/Metonymy
-Metonymy is used as a figure of speech or as a replacement word.
Example: "The mighty hand leads to a sloping shoulder,
The finger joints are cramped with chalk;
A gooses quill has put an end to murder
That put an end to talk."
*In this poem The Hand That Signed the Paper, Thomas critisizes the ruler and the amount of power associated with rulers and people of high power. The "gooses quill" mentioned in the poem is a metonymy that refers to power that is associated with the ruler's hand.