What is a suffix for rely?

There isn't a specific suffix that directly attaches to "rely" to form new words.

However, you can use other suffixes to create related words:

* -ance: Reliance (the act of relying on someone or something)

* -able: Reliable (worthy of trust; dependable)

* -er: Relier (this is uncommon, but could be used to refer to someone who relies on something)

Remember that the meaning of the word will change depending on the suffix you choose.