suffix
Attaches to the -masu stem of a verb or to a noun to express that the action or thing is worthwhile, produces a satisfying result, or has value. Often used in set phrases like 生きがい (reason for living) or やりがい (sense of fulfillment).
See also: 甲斐 (かい)
この仕事はやりがいがある。
This job is rewarding.
努力した甲斐があって、試験に合格した。
My efforts paid off and I passed the exam.