His friends mocked him for spending all his time on skirt-chasing instead of finding a proper job.

skirt 本义是"裙子"，在俚语中常用来指代"女性"。 chasing 是动词 chase 的现在分词形式，chase 的意思是"追逐、追求"。 skirt-chasing 是一个俚语表达，字面意思是"追逐裙子"，实际指"追求女性、泡妞"的行为，带有贬义色彩。