Next time I go to the mechanic I am going to ask to have my tires circumgyrated. If he gives me a chance to explain before punching me in the face, I can tell him that although it sounds vaguely dirty, circumgyration is just an excessively long word for rotation. I found it while clicking on on the Oxford English Dictionary's online "Lost for Words" button -- which gives you a random word -- last night.
1. The act of turning round as a wheel; rotation, revolution on an axis. b. Giddiness, vertigo. Obsolete and rare usage 2. Moving in a circular or circuitous course; circling, wheeling, turning about, traveling round. b. Circuit. Obsolete usage 3. fig. (No explanation for what this meant. I couldn't find it in the guide to the dictionary.) 4. Convolution, contortion.
It seems to be an old word, as most of the quotations given were from the 17th century. This was under the first definition: