As I have previously defined an Italian word (a language I do not know), disegno, let’s look at another one.
The Oxford English says “2. The treatment or disposition of the light and shade, or lighter and darker masses, in a picture.” and cites John Opie’s 1806 Royal Academy Lectures on Art “Chiaroscuro includes not only light and shadow as it effects each separate part, but the proper division and distribution of the whole surface of a picture into bright or dark masses, whether the darkness be produced by shadow, or by the proper colour of…the objects represented.”
The word comes from Italian for “light-dark”, chiaroscuro is defined as a bold contrast between both light and dark. A certain amount of chiaroscuro has the effect of light modeling in painting, where three-dimensional volume is suggested by highlights and shadow. A departure from the pre-Renaissance flat field styling.