Why "a chief"? Does it even make sense in English?
Ok after reading through the last chapter again I kinda figured it out. MC told the dwarves that he got the dragon fang from a (village) chief, so I'm assuming they used the same word as "chief" for the monster but with different meaning (boss or something?)
You could have just called him the boss, and leave a note saying "they using the same Japanese word as chief from the last chapter" or some shits, how hard was that.