Although he could afford better hotels, he chose to slum in the poor neighborhood for the night.

slum 在这里用作动词，原为名词指"贫民窟、贫民区"。动词化后表示"在简陋环境中凑合过夜"的意思，带有临时将就的含义。这种名词转动词的用法在英语中较为常见，通过词性转换赋予原名词新的动作含义。