Google uses the "did you mean" feature, which normally corrects misspellings, to illustrate a nerdy joke: defining the word "recursion" using "see recursion" and pointing to the same definition.
"Arecursive process is one in which objects are defined in terms of otherobjects of the same type. Using some sort of recurrence relation, theentire class of objects can then be built up from a few initial valuesand a small number of rules," explains MathWorld.
For more information, search Google for [recursion].