The meaning of the word “Yoga” is “union”. It is derived from the Sanskrit root “yuj,” (pron. “yug”) meaning “to join”, “to unite” but also “to subjugate”, with the meaning also “to control” and “to disciplinate”. The English word “yoke” is also derived from the same Sanskrit (Indo-European) root.
Yuga in Hinduism is an epoch or era within a four-age cycle. A complete Yuga starts with the Satya Yuga, via Treta Yuga and Dvapara Yuga into a Kali Yuga. Our present time is a Kali Yuga, which started at 3102 BCE with the end of the Kurukshetra War (or Mahabharata war).