The phrase "unearned portion" refers to a part or amount that someone does not deserve or has not earned through their actions or efforts. Full definition
However, (and maybe this isn't as widespread as I've heard) don't some contracts require the author to pay back unearned portions? (jamigold.com)
Industry convention also dictates that, if a book under - performs, the author does not have to pay back the unearned portion of the royalty. (thebalancecareers.com)
This unearned portion depends on when in the semester you drop out. (thecollegeinvestor.com)