The Zugot , also called Zugoth or Zugos in the Ashkenazi pronunciation, refers both to the two-hundred-year period during the time of the Second Temple in which the spiritual leadership of the Jews was in the hands of five successions of "pairs" of religious teachers, and to each of these pairs themselves.
Origin of the name
In Hebrew, the wordzûghôth indicates pairs of two identical objects, plural of zûgh, a pair. The word is related to Arabiczawj as singular and zawjaat as plural, "spouse", and Aramaiczôghāʾ, "pair, spouse", from a root meaning "to join" ultimately borrowed from Greekzugón, "yoke".
Roles
The zugoth were five pairs of scholars who ruled a supreme court of the Jews as nasi and av beit din respectively. After this period, the positions nasi and av beit din remained, but they were not zugot. The title of av beit din existed before the period of the zugot. His purpose was to oversee the Sanhedrin, the court of religious law also known as the "beit din". The rank of nasi was a new institution that was begun during this period.
The term zûghôth refers to pairs generally. The Babylonian Talmud contains an extensive discussion of dangers of zûghôth and of performing various activities in pairs. The discussants expressed belief in a demonology and in practices of sorcery from which protection was needed by avoiding certain activities. The demonology included a discussion of Ashmidai, referred to as king of the shedim "demons". However, later generations did not make efforts to avoid harm from zugot, and their rabbis suggest various reasons why this is the case. Menachem Meiri stated that belief in the harm of pairs was widespread among the masses of the time and the Sages sought to allay their fears and draw them away from their excesses. Tosafot ruled that the rules regarding zugot need not be followed, as these evil spirits are no longer prevalent. The Tur included the zugot rules in his code, but the Beit Yosef disputed this based on Tosafot. The Shulchan Aruch and Mishneh Torah do not mention concern for zugot. Most recent poskim, including Ben Yehoyada of Yosef Hayyim, do not require concern for zugot.