Definition of rely on/upon
1
: to need (someone or something) for support, help, etc. : to depend on (someone or something)
- My mother relied on me for financial support.
- They rely on a well for all their water.
2
: to trust or believe (someone or something)
- She's someone you can rely on.
- I relied heavily upon your advice.
- You could always rely on him to disagree.
3
: to expect (something) with confidence : to be certain that (something) will happen or exist
- The economy may improve next year, but it's not something you can rely on.
