Hyperborea is a compawnd word : Hyper-borea (see https://en.wikipedia.org/wiki/Hyperborea ).
hyper comes from the Greek υπερ. It means super, excessive.
borea comes from the Greek βορράς (north).
Therefore Hyperborea means the land or people that are too far to the North, or beyond North.
Now what do you mean with the phrase: the first letter in ancient Greek is "g"