Nathan ben Jehiel of Rome was a Jewish Italian lexicographer. He authored the Arukh, a notable dictionary of Talmudic and Midrashic words, and consequently he himself is often referred to as "the Arukh".
First page from the first edition of the Arukh (ca. 1480)
Alexander Kohut was a rabbi and orientalist. He belonged to a family of rabbis, the most noted among them being Rabbi Israel Palota, his great-grandfather, Rabbi Amram, and Rabbi Chayyim Kitssee, rabbi in Erza, who was his great-granduncle. The last-named was the author of several rabbinic works.
Alexander Kohut
Rabbi Kohut, c. 1893