get him down

使人沮丧/让某人情绪低落

`get someone down` 是一个短语动词，意思是让某人感到沮丧或不开心。这里 Holt 说 Boyle 不会屈服于逆境，因为他「不让逆境击垮他」(`doesn't let adversity get him down`)。