Describes someone who is extremely thin, often due to illness or malnutrition.
La mujer macilento que vi en la calle parecía necesitar ayuda.
The emaciated woman I saw on the street seemed to need help.
Su aspecto macilento preocupaba a todos, ya que parecía no comer adecuadamente.
His emaciated appearance worried everyone, as he seemed not to eat properly.