opaqueness

The word 'opaqueness' is a relatively modern English formation, built upon the older adjective 'opaque'. 'Opaque' entered English in the late 15th century from Latin opacus, meaning "shaded, dark, obscure." The Latin term's origins are uncertain but may be related to a Proto-Indo-European root implying covering or obstruction. To this concrete adjective describing a material's physical property, the native English suffix '-ness'—a highly productive suffix from Old English used to form abstract nouns denoting a state or quality—was appended. Thus, 'opaqueness' literally means "the state or quality of being dark or impervious to light," a meaning which easily extended metaphorically to intellectual or communicative obscurity.

Structure: opaque + ness - opaque: From Latin opacus (shady, dark). Functions as the adjectival root. - ness: From Old English -nes, a noun-forming suffix indicating a state or quality. Functions as a suffix.