Otherworldliness is recorded from 1819. Phrase other world is from c. 1200 (oþre weorlde) as "afterlife, spirit-land, world to come;" c. 1300 as "world of idealism or fantasy, a state of existence different from normal," but otherworldliness seems to have been formed from worldliness. Leigh Hunt used it first in print, in "The Examiner" [Dec. 19, 1819], but a reported use of it by Coleridge, printed in Thomas Allsop's selections from Coleridge's letters and conversations (1836), which apparently cover the years 1818-22, was better-known thereafter, and the word is sometimes attributed to Coleridge:
As there is a worldliness or the too much of this life, so there is another-worldliness, or rather other worldliness, equally hateful and selfish with this worldliness.
Hunt, in his "Autobiography" (1850), writes:
I hope I am not giving fresh instance of a weakness which I suppose myself to have outgrown; much less appropriating an invention which does not belong to me; but an accomplished authoress one day (Mrs. Jameson), at the table of my friend Barry Cornwall, quoted the term "otherworldliness" from Coleridge. I said Coleridge was rich enough not to need the transference to him of other men's property; and that I felt so much honoured by the supposition in this instance, that I could not help claiming the word as my own. If Coleridge, indeed, used it before me, I can only say that I was not aware of it, and that my own reflections, very much accustomed to that side of speculation, would have suggested an identical thought.