The younger generation is re-appropriating these once-biased words to give them positive meanings.

re-appropriating 是动词 re-appropriate 的现在分词形式。re- 是前缀，表示"再次、重新"；appropriate 作为动词意思是"占用、挪用"。re-appropriate 合起来表示"重新占用、重新挪用"，在这里指"重新定义"这些词汇的用法和含义。