noun In Hindu theology, a period of a few hundred or thousand years, or an epoch or era within a cycle of four ages, catur-yuga catur-yuga: the Satya Yuga (or Krita Yuga), the Dvapara Yuga, the Treta Yuga and finally the Kali Yuga, with lengths ranging from 432,000 to 1,728,000 years.