Substitute
Replacement
noun, の adjective
You've seen that 代わる means "to substitute for" or "to replace." This is the noun version of that (no う sound on the end). So, what is the noun version of those verb words? It would be substitute or replacement.
かわり
You should be able to figure out the reading from learning 代わる in the previous level.
代わりの先生をさがしています。
We’re looking for a substitute teacher.
この世のどこにも、かれの代わりはいないんです。
There is no replacement for him anywhere in the world.
日本語を教わる代わりに、英語を教えることができますよ。
I can teach you English and in exchange you can teach me Japanese.