Another word for “ikigai”

A person's calling in life - "a strong inner urge to follow an occupation, etc; vocation"

Source: TheFreeDictionary

Fortunately for us, concepts in Japanese tend to be expressed in compound words. As an example, the word in question here, ikigai, is a compound word, composed of these parts:

生き - iki - living, being alive, vitality
甲斐 - gai - worth, use, effect

As ikigai is a concept that pertains to one's reason for living we could take into consideration some of the literal meanings for iki and gai separately to understand that the possible more accurate translation is what gives your life worth.