-fest definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
an occasion of much or many (of the thing specified): often used to form informal or slang words: songfest, slugfest
Origin: ; from German fest, a celebration ; from Classical Latin festum: see feast
-fest definition by American Heritage Dictionary
A gathering or occasion characterized by a specified activity. Often used in combination: a music fest; a chilifest.
Origin: From German Fest, festival, from Middle High German fest, from Latin fēstum; see feast.