Mordecai Najar was a rabbi in Majorca in the first half of the 15th century, a contemporary of Simon ben Ẓemaḥ Duran, who answered some of his questions in Tashbaẓ (part i., Nos. 119, 173-174; part ii., Nos. 141, 225-232).
References
Mordecai Najar Wikipedia(Text) CC BY-SA