Dictionary.com
definitions

bashment

noun
  1. another name for dancehall

Word Origin for bashment

C20: from bash, a party + -ment
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012