rely upon (someone or something)(redirected from reply upon someone)
rely upon (someone or something)
1. To be dependent on someone or something; to require someone or something for support or help. (Slightly more formal and old-fashioned than the variant "rely on.") There are a lot of cities around the country that rely upon the steel industry—if it collapses, so do their entire economies. You can't just rely upon your parents to bail you out whenever you get into trouble.
2. To have trust or faith in someone or something; to believe that someone will do something or that something will happen. You can always rely upon the weather to turn foul whenever you plan something outdoors. People who rely upon the government to act in their best interests are naïve, foolish, or both. I just can't rely upon this computer to do what it's supposed to do.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.