I don't understand why asking people to eat a well-balanced vegetarian diet is considered drastic, while it is medically conservative to cut people open and put them on cholesterol-lowering drugs for the rest of their lives.
—Dean Ornish, MD
metonymy
A figure of speech in which one word is substituted for another with which it is closely associated. For example, in the expression The pen is mightier than the sword, the word pen is used for "the written word," and sword is used for "military power."