Umbrosity

the interstitial divisions being continuated by the accession of oil, it becometh more transparent, and admits the visible rays with less umbrosity

Source: wiktionary

Shrubberies.[…]The judicious introduction of views of more distant scenery; which is most frequently desirable, unless in such parts as, by way of contrast, are preserved in umbrosity.

Source: wiktionary

Cotton is grown here as an annual, yet in some strong lands it is allowed to remain in the ground for two seasons[…]from the umbrosity of its foliage, and its hoeings, it leaves the land, in a fit and open state to receive a winter crop.

Source: wiktionary

The architecture of winecellar-cum-dungeon prohibited a smooth transition from illumination to umbrosity. Lasse's logic was sound: Concentrate on the penumbral areas; any useful item in the deep shadow cannot be seen and any such object in the light will have been removed.

Source: wiktionary