obscuridad

n. obscurity, that which is obscure

= darkness, obscurity, murkiness.
Ex: At every instant the darkness of the line being drawn is made equal to the darkness of the point on the picture being observed by the photocell.
Ex: Obscurity in the law is against the public interest.
Ex: Given the murkiness surrounding the identification of which spaces are public and which are private, it seems rather futile to attempt to define public space by a single characteristic = Dada la falta de claridad que rodea la identificación de qué espacios son públicos y cuáles son privados o semiprivados, parece bastante inútil intentar definir lo que es un espacio público con una sola característica.
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* al amparo de la oscuridad = under cover of darkness.
* caer en la oscuridad = fall into + obscurity, sink into + oblivion, sink into + obscurity, fade into + obscurity, fade into + oblivion.