But he added, "that since I professed so inviolable an attachment to truth, I must give him my word and honour to bear him company in this voyage, without attempting any thing against my life; or else he would continue me a prisoner till we arrived at Lisbon."
There are no more uses of "inviolable" in the book.
Show samples from other sources
Their lessons always proved invaluable and inviolable.
Piper Kerman -- Orange Is the New Black
All this was inviolable, like any set of natural laws.