In Sotah 46a, it says the following:
אָמַר לְהוּ הַהוּא מֵרַבָנָן ור׳ יַעֲקבֹ שְמֵיהּ לְדִידִי מְפָרְשָא לִי מִינֵּיהּ דְרַבִי יוֹחָנָן מְשִיכַת עוֹל לְרָחְבוֹ טֶפַח
One of the rabbis said to them, and his name was Rabbi Yaakov, The statement of Rabbi Yochanan was explained to me as meaning: Drawing by a yoke to the extent of a handbreadth in its breadth.
Why does the Gemara refer to R' Yaakov in this odd fashion?