Juga, or Jugalis, is an epithet of Juno in Her aspect as Marriage-Goddess,
who was believed to join a couple together in matrimony. Her name means "the
Uniter". As Goddess of Women, Juno especially presided over marriages and
children, and She has numerous other epithets relating to that function.
As Juno Juga She had an altar on the Vicus Jugarius, and though
it was believed by the ancients that the altar gave its name to the street,
in reality it was probably the other way around, as the Vicus Jugarius was very
oldperhaps even older than Rome itself, since it was part of the original
trade route to the Tiber river. Jugarius can mean either "yoke"
or "ridge"; as this road ran along the shoulder of the Capitoline
Hill, it probably meant something like "the Road along the Ridge".
Related words in Latin are jugalis "yoked together" and jugo
"to marry" or "join"; some words deriving from this Latin
root are in English yoke, join, juncture, and conjugal.
And yes, it is also ultimately related to the word "yoga", the Eastern
meditative practice of stretching, which derives from the Sanskrit root yuj,
"to yoke" or "to unite", and in which case refers to the
joining together of body and spirit.
It is not known precisely where on the Vicus Jugarius the altar
to Juno Juga was located; though it was probably not near to the Forum or to
the Porta Carmentalis, the "Gate of Carmenta", so-called because of
a shrine to Carmenta nearby. One source says that
Juno Jugalis had a temple in the Forum at the base of the Capitoline Hill, and
that the Vicus Jugarius took its name from that. I can find no other reference
to this temple; perhaps the source has been mistranslated and what is really
meant is the altar on the Vicus Jugarius.
Alternate spellings: Iuga, Iugalis.