IPA: /ˌsuːpəˈrɛɡəˌreɪʃən/
KK: /suːpərɪˈɡeɪʃən/
The act of doing more than what is required or expected, often in a moral or ethical context.
Volunteering at the shelter is an example of supererogation, as it goes beyond what is required.
Supererogation is formed from "super-" (meaning above or beyond) and "erogare" (meaning to pay out or expend). The term refers to the act of performing more than is required or expected, particularly in a moral or ethical context.
Think of doing something 'beyond' ('super-') what is required or expected — that's what supererogation means.