We drove through a grim and forgotten part of the city, where the buildings were all boarded up.

grim 的意思是"阴沉的、令人沮丧的"，常用来形容环境或气氛压抑、不愉快。这个词带有一种冷酷无情的意味，暗示着缺乏希望或欢乐。