Noun, する verb, and の adjective
だいよう
サワークリームをヨーグルトで代用しました。
I substituted sour cream with yogurt.
きもののこしひもは、ストッキングでも代用かのうです。
You can use stockings as a substitute for the cord you wear under your kimono.
糊がないので飯粒で代用した。
We didn’t have glue so we substituted grains of boiled rice for it.
A substitute task is a substitution.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.