"Supplemental income" refers to money earned in addition to the main source of income. It is extra money earned on the side to support or augment one's primary earnings. Full definition
Perhaps she's just looking for supplemental income as she's married or retired — we don't know. (victoryediting.com)
It is an ever - expanding industry, and one that can result in a substantial source of supplemental income for those who choose to get involved. (thecollegeinvestor.com)
Lots of moms earn supplemental income by selling products they use, like makeup or essential oils through in - home parties and demonstrations for friends and family. (creditdonkey.com)