[f. WINDOW sb. + -FUL.] As much as fills or will fill a window or the space which a window gives a view of.
1845. Northern Star, 8 March, 3/2. Here was a proper retailing of sunbeams and dispensed it to the poor at the rate of sixteen and sixpence per windowful.
1878. Mrs. Oliphant, Primrose Path, iv. That windowfull of sky had darkened, it was almost night.
1886. Rosa Mulholland, Marcella Grace, 253. xxi. In poorer homes on the outskirts of the city, sometimes even in wretched lanes, one sees windowfuls of flowers, but the mansions of the upper ten remain guiltless of such frivolity.