Meaning of -FEST in English
a combining form occurring in compound words that have the general sense "an assembly of people engaged in a common activity"; the first element of the compound usually specifies the activity: gabfest; lovefest; slugfest; songfest.
[ Fest festival, holiday (see FEAST), as in Sängerfest choral festival ]
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012