Rely upon is a phrase that means to DEPEND on something or someone for support. The crossword solutions for this phrase are DEPEND (6 letters), GOBY (4 letters), and LOOKTO (6 letters). DEPEND means to be contingent on something, GOBY means to follow a certain course of action, and LOOKTO means to direct one's attention towards something. All three words can be used to describe the concept of relying upon something or someone.