circum-: A nice little prefix that means "around, about, surrounding." Notice its similarity to the word circle. This prefix gives us a number of polysyllabic gems, such as circumnavigate (to sail or fly around something), circumscribe (to draw a line around something, or, more figuratively, to set something's boundaries), circumfluent or circumfluous (to flow around, surround, or encompass something), circumambulate (to walk around something), and even circumcise (which at its base means to cut around something).
Then there's circumlocution. Locution has to do with speaking, and the style one uses when speaking. Circumlocution, then, is all about talking around something: a roundabout way of expressing something. We hear a lot of circumlocution from both sides in the presidential debates. I would wager that nearly every "answer" that a candidate gives is circumlocutory, ultimately expressing some idea that has little to do with the moderator's original question. A candidate is given a question about, say, foreign policy, and he (or she) begins to talk about his (or her) foreign policy ideas and experience, but through some amazing (and some not-so-amazing) circumlocution ends up making a statement about a completely different subject, say, offshore drilling.
Keep your ears open for circumlocution at the next debate. Politicians seem to have a knack for it.