אמר ליה שמואל לרב יהודה: שיננא
“Shmuel said to Rav Yehuda: Shinnana“
According to the Koren note:
“According to Rashi and others, shinnana means sharp or witty, and reflects the degree to which Shmuel respected his primary student. The ge’onim* however, explain that according to the oral tradition, shinnana means big toothed, and was a nickname for Rav Yehuda based on his appearance.”
According to the “Kitzur Shulchan Aruch”, Rabbi Shlomo Ganzfried’s classic compendium of Jewish Law from the late 19th Century CE:
It is forbidden to call a person who has an uncomplimentary nickname by that name – even though he is already accustomed to being called by it and is no longer embarrassed – if one’s intent is to shame him. This is also considered as wronging someone with words.”
I suppose that we could say that if either (i) Shmuel was using the name as per Rashi’s answer we would have no problem with this nickname; or (ii) if it was an actual description of Rav Yehuda no malice was meant.
What I find most curious is that we have no way of knowing so why would the Talmud repeat the story and put doubt in our minds? Maybe we just have to be the sort of people who live by the phrase dan l’chaf zechut!
* Gaonim (gāō`nĭm) [Heb.,=excellencies], title given to the heads of the Jewish academies at Sura and Pumbedita in Babylonia immediately following the period of the Saboraim [Heb.,=expositors], in Judaism, title given to the Jewish scholars of the Babylonian academies in the period (6th–7th cent. A.D.) immediately following the Amoraim and preceding that of the Gaonim. Little is known about them.
The Gaonim asserted the primacy of the Babylonian Talmud over the Palestinian Talmud and contributed to the standardization of Jewish law and liturgy. The greatest Gaon at Sura was Saadia ben Joseph al-Fayumi, 882–942, Jewish scholar, b. Egypt. He was known as Saadia Gaon. He was the head of the great Jewish Academy at Sura, Babylonia, which under his leadership became the highest seat of Jewish learning.
Of those who held office at Pumbedita, Sherira Gaon (968–98) and his son Hai Gaon (998–1038) are most notable. Under Sherira the waning prestige of the Babylonian academies was restored, and it was maintained by Hai until his death. Thereafter European Jewry came to play an ever more dominant role in Jewish life.