Definition of "sacredly"

Scip[io]. […] Remember Syphax / Thy vow hath made thee Romes. / Syph[ax]. Which Ile preserve / As sacredly inviolate, as if / Eternall seales had ratifi’d it.

1637, Thomas Nabbes, Hannibal and Scipio‎, London: Charles Greene, act II, scene 3

[H]e proteſted to me, that if he vvas naked in Bed vvith me, he vvould as ſacredly preſerve my Virtue, as he vvould defend it if I vvas aſſaulted by a Raviſher; […]

1722 (indicated as 1721), [Daniel Defoe], The Fortunes and Misfortunes of the Famous Moll Flanders, &c. […], London: […] W[illiam Rufus] Chetwood, […]; and T. Edling, […], published 1722, page 136

[…] I have a communication of a very private—indeed, I will say, of a sacredly confidential nature, which I desire to make to you.

1871–1872, George Eliot [pseudonym; Mary Ann Evans], chapter LXI, in Middlemarch […], volumes (please specify |volume=I to IV), Edinburgh, London: William Blackwood and Sons, book VI

Each girl has to read her story out loud and then we talk it over. We are going to keep them all sacredly and have them to read to our descendants […]

1908 June, L[ucy] M[aud] Montgomery, chapter 26, in Anne of Green Gables, Boston, Mass.: L[ouis] C[oues] Page & Company, published August 1909 (11th printing)

Satisfaction because the ritual of Gormenghast was proceeding as sacredly and deliberately as ever before […]

1946, Mervyn Peake, “Mr Rottcodd Again”, in Titus Groan, London: Eyre & Spottiswoode