However, the term 'avot' is not usually used as an honorary designation for 'rabbis' or 'sages'; in rabbinical usage, it refers to the Patriarchs of the Bible. Rather, in the Mishnah, the word "avot" generally refers to fundamentals, or principal categories. (Thus, the principal categories of creative work forbidden on Shabbat are called "avot melacha", and the principal categories of ritual impurity are referred to as "avot" "tum'ah".) Using this meaning, "Pirkei Avot" would translate to "Chapters of Fundamental Principles". Additionally, the possibility that the title was intentionally worded to support multiple renderings - both "fathers" and "fundamental principles" - cannot be ruled out.