the GNU version of the Collaborative International Dictionary of English
n. Conceitedness.
The Century Dictionary and Cyclopedia
n. The quality of being bumptious.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. offensive boldness and assertiveness
Word Usage
"Leon looked after him rather disconsolately, as though at a loss to understand what could have happened to take all the fight and "bumptiousness" out of the former bully."