Unbetrayable

So he betrays, / Not Truth, the unbetrayable, but himself: […]

1926, Hart Crane, “Voyages” VI in The Collected Poems of Hart Crane, New York: Liveright, 1946, p. 110, The imaged Word, it is, that holds Hushed willows anchored in its glow. It is the unbetrayable reply Whose accent no farewell can know.

It is seven years, thought Sandy, since I betrayed this tiresome woman. What does she mean by “betray”? She was looking at the hills as if to see there the first and unbetrayable Miss Brodie, indifferent to criticism as a crag.