Worth Doing
noun
やり is from やる, meaning "to do," and 甲斐 means "effect" or "worth." So, if the thing you do has an effect and is worth something, then it is worth doing.
やり甲斐 is a noun, so it's often used in phrases like やり甲斐がある (to be worth doing) or やり甲斐を感じる (to feel worthwhile).
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own — just watch out for the rendaku changing 甲斐's reading to がい.
この仕事は、誰かのために役に立つことができるので、とてもやり甲斐があります。
This job is really worthwhile because I can be useful to other people.