the world > matter > light > darkness or absence of light > darkness or gloom > [adverb] > darkly, duskily, or dimly
1844 E. B. Barrett Drama of Exile in I. 48 Shapes, which have no certainty of shape, Drift duskly in and out between the pines.
1880 W. Watson 58 An eagle with wide wings outspread Athwart the sunfire hovering duskly red.