The earliest recorded Jewish name for it is hotam Shelomo or seal of Solomon, a term that entered Hebrew and many European languages as a translation of the Arabic khatam Suleyman… Moreover, the Arabs called another of Solomon's seals najmat Da'ud or the Star of David, and eventually, taken over by Christian Europe, these two terms became differentiated, with seal of Solomon referring to a five-pointed pentagon and star of David to a six-pointed hexagon.
Uri Ofir suggested in his research about The Jewish Origin of the Star of David that the source for this "odd" translation is in the commentaries of Rashi and Iben Ezra. Rashi and Iben Ezra wrote that Bilam's prediction ["There shall come a Star out of Jacob, and a Scepter shall rise out of Israel" (Numbers 24:17)] is about King David. These two commentators were so influential that every Jew knew that there is a strong connection between the concept of the Star and the concept of David. No wonder that when translators dealt with these materials they unanimously decided on the same ("odd") translation.