the GNU version of the Collaborative International Dictionary of English
n. a sudden unexpected piece of good fortune.
The Century Dictionary and Cyclopedia
Extra profit; bonus: used as an exclamation by boys. The cry “Bunce!” when something is found by another gives the right to half of what is discovered.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a sudden happening that brings good fortune (as a sudden opportunity to make money)
Word Usage
"We know that this runaway development across England provides some nice tax bunce for Broon which can be transferred to nulab voting communities elsewhere."