Howard's "Bori" is a reflection of the nordic mythology "Buri", and has nothing to do with Greek Boreas.
"In the beginning, there was no upper sky,
neither earth below, nor grass anywhere
there was no sand, no salty waves,
just empty abbyss bottomless
From Elivagar fluid came dripping, of which a giant arose
Vergelmir was his name, who also as Ymir was known
Underneath the Giant's arm a man and a woman grew
and foot with the foot begat a sixfold son
Audumla gave nourishment, who had thawed from the ice
licking salty stones, out of which a head
on the third day a full-grown man,
who was Buri, fair and strong, arose"