Definition of "orison"

The faire Ophelia! Nymph, in thy Orizons / Be all my ſinnes remembred.

c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene i], page 265, column 2, lines 88–89

"I hope," said a voice by her side, "your absent brother will not engross all your orisons."

1834, L[etitia] E[lizabeth] L[andon], chapter XXVII, in Francesca Carrara. […], volume I, London: Richard Bentley, […], (successor to Henry Colburn), page 320

Only the stuttering rifles' rapid rattle / Can patter out their hasty orisons.

1917, Wilfred Owen, Anthem for Doomed Youth

We shall see later that the absence of definite sensible images is positively insisted on by the mystical authorities in all religions as the sine qua non of a successful orison, or contemplation of the higher divine truths.

1902, William James, “Lecture 3”, in The Varieties of Religious Experience: A Study in Human Nature […] , New York, N.Y.; London: Longmans, Green, and Co. […]

Only in certain occult and mystic states: in orison, contemplation, ecstasy and their allied conditions; does the self contrive to turn out the usual tenants, shut the "gateways of the flesh," and let those submerged powers which are capable of picking up messages from another plane of being have their turn.

1911, Evelyn Underhill, Mysticism: A Study of the Nature and Development of Man's Spiritual Consciousness, Part I, Chapter 3