verb/empaˈɲaɾ/
to put a nappy/diaper on; to steam up; to tarnish; to fog up, steam up, cloud over; to well up
“Perfeccionábase, malgrado lo cual una sombra de tristeza parecía empañar su gloria.”
From paño and pañal, the diversity of senses perhaps arising through the metaphor of covering what once was clear.