from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To fill underneath; to stuff.
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To fill underneath; to stuff.
from The Century Dictionary and Cyclopedia
- To stuff underneath.
Old English underpicchen. See under, and pitch to throw, fix. (Wiktionary)
Art did everything to underpitch its 2010 Biennial.