... and the Google whack!

Anybody know what a "Google whack" is? It was explained to me as follows. When a searcher types in a search term or keyword phrase in Google's search box, usually far too many results are returned but occasionally no results are returned at all. Even more rarely Google will return exactly one (1) result and one result only: that's a Google whack! Howzat for a pretty useless bit of information?