I've heard a similar tale about 'wisdom tooth'. The story goes that it's a translation of the Dutch 'verstandskies'. 'Kies' means tooth (molar?), and 'verstand' can mean 'far-standing', so referring to the position of the tooth.
However, because 'verstand' more commonly means 'mind', it was mistranslated.
Now, Germans also use the 'wisdom' version, and Belgians use 'wijsheidstand', where 'wijsheid' is another of wisdom, so probably this story is incorrect. Many of us Dutchies still choose to believe it, however, and so we just have to conclude that both the Germans and Belgians are just kind of silly for making the same mistake.
It's from Greek σωφρονιστήρ /sophonister/ through Latin (dens sapientiae). It's been "Wisdom tooth" all along. The story goes that these teeth appear approximately at the age where one becomes "wise."
Ha. Few of the people whose wisdom teeth came and went (painfully) are wise already. Increased life spans and all that…
Then again, sophos does not just mean wise in Greek, but also just clever, cunning, or prudent. ;-)