oscurecer betyder på engelska

benight▼(to darken, see also: darken)
verb

darken [darkened, darkening, darkens]▼(to make dark by reducing light)
verb
[UK: ˈdɑːkən] [US: ˈdɑːrkən]The sky started to darken. = El cielo empezó a oscurecerse.

shade [shaded, shading, shades]▼(to darken or to lightly colour)
verb
[UK: ʃeɪd] [US: ˈʃeɪd]