The words are Ukranian Russian.
"niye-bayusya" means "I dont fear". As stated, Chabad has a rich history with these words. They were sung by a Chossid - out loud, out doors, in Soviet Russia upon learning of the previous Rebbes release from exile.
So the are symbolic for inner strength and courage.
And, in their creative way, they introduce contemorary meaning to things that are otherwise appreciated in mostly historical and cultural terms..
