The Oxford Dictionary states that the word 'Syn' has its origin in the Greek word 'Sun' meaning 'With'. I for One am certain that the meaning of the word 'Syn' is indeed 'Sun' but that the origin of the word 'Sun', and all other words, is 'Self' otherwise known as Sve, Śvā, Sva, Śvā, Shva.
~ Wald Wassermann