1. A noisy celebration.
2. A large assembly, often international, especially of Boy Scouts or Girl Scouts.
3. A mass gathering or assembly, as of a political party or association.

[Origin unknown.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.