slantwise adjective 1adverb 1forms 2 adjective1 •Diagonal, in a direction or orientation between cardinal axesI can see it all now,—the slantwise rain / Of light through the leaves, / The sundown's blaze on her window-pane, / The bloom of her roses under the eaves. — 1858 adverb1 •Diagonally, in a direction or orientation between cardinal axes[…] he had received a cut slantwise along one temple and cheek, leaving a long scar like a streak of dawn's light falling athwart the dark visage. — 1924 formsmore slantwise · most slantwise