From Latin obscūritās, from obscūrus (“dark”).
escuridat f (usually uncountable)
- darkness
- shadow; a dark patch, spot or area on or underneath a surface
c. 1250, Alfonso X, Lapidario, f. 114r:Et semeia al criſtal. pero deſdizel ya quanto. ca ha en medio una eſcuridat. que semeia linna negra.- Furthermore, it resembles glass, though not entirely, for it has in the center a dark area resembling a black streak.