Berkeley Diary


May/11/2005  My Finds to Word Lag(4) Wisdom Teeth VS. Oya-shirazu

@@Today I ran into Sue Rim, Tae's younger sister on the campus. She is baby-faced and looks like a high school student. But as a matter of fact, she is a "Sue"perior student. She will graduate from the department of economics, UCB in a week. She told me her parents would come to attend the graduation ceremony. She looked very happy and  she has a bright future before her, but she sometimes makes a wry face. I felt curious, and asked her, "what the matter?"  She answered, "I've just had my wisdom teeth removed. That hurts!"

     I could not understand what she said. When I asked her again, she pointed to her right cheek. And she said, "It is painful, here!" Then I understood "wisdom tooth" meant "oya-shirazu" in Japanese.

     After I came back to my apartment, I looked up "wisdom tooth" in an English dictionary on the internet ( It explained it as follows:
     "wisdom_tooth---- any of the last 4 teeth on each side of the upper and lower jaw; the last of the permanent teeth to erupt (between ages 16 and 21)."

      In Japanese, "oya-shirazu" means "His or her parents don't know it." I also looked up this word in a Japanese dictionary (Kojien). I translated it into English as follows:
      "oyashirazu-ba----a common name of the third molar tooth. The 4 teeth (upper and lower, left and right) of man's 32 teeth to erupt at last."

      What is the derivation of this word in Japanese? According to an account, all parents feel pleasure when their baby's teeth come out. But after the children grow up to teenage, when they cut their third molars, their parents lose an interest in their daughter's or son's teeth. According to another account, in ancient times, the lifespan of humankind was very short. When the children cut their third molars, their parents were already dead.
       I don't know which account is true. Therefore, to ascertain the truth, we have to research the historical materials to make sure when the oldest use of the word began. In any case, I find it very interesting.

      Eruption of the third molars is often accompanied by intense toothache. According to dental medical research, contemporary man' jaw has become smaller. We regard these teeth a negative sign. The word "oya-shirazu" is similar to "on-shirazu" in sound. The latter has very negative meaning. It means "ungrateful person." Each of these words gives a negative impression.

      From a quite different perspective, when our third molars erupt, we acquire the wisdom. Perhaps we can say English is intellectual, but Japanese is emotional!

To: Soka University HP (English)
To: Department of the Japanese Language and Literature HP
To: Masaki YAMAOKA's HP: Index