from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To undo, take back, or annul, as a payment.
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To undo, take back, or annul, as a payment.
from The Century Dictionary and Cyclopedia
- To undo; annul by payment.
un- + pay (Wiktionary)