From wiki: I love idioms. Especially related to food. Please Register or Log in to view the hidden image! But I am wondering how one can distinguish an idiom. e.g. The Boston Tea Party, is that an idiom? "Let them eat cake" is that an idiom? How about teabaggers? Another thing I came across while looking up idioms is the Principle of Compositionality: From wiki: In mathematics, semantics, and philosophy of language, the Principle of Compositionality is the principle that the meaning of a complex expression is determined by the meanings of its constituent expressions and the rules used to combine them. Most jargon, slang, aphorism, idiom contradicts the principle of compositionality. Is that a way to identify an idiom? Or is that too simplistic? Finally, is there a reason so many idioms/expressions are related to food?