What's "chase down" mean and when's it used?

Native speaker’s answer
Rebecca
"Chase down" means to follow and catch or search until someone or something is found. It can be used physically if you literally run after a person or object. Or it can be used in the sense of searching and investigating, or it can be used metaphorically pertaining to goals and dreams in one's life. Ex: I've been trying to chase down the limited edition sneakers released last month. But I haven't found them anywhere. Ex: The police chased down the suspect and caught him. Ex: If you try to chase down happiness in being famous, you might not ever be happy.