A rhythm game term, when a person is used to how Friday night funkin' typically charts its song by giving frequent breaks that they don't have enough stamina compared to the difficulty of the patterns they can hit
This idiots plays way too much Friday night funkin' and now he's got fnf syndrome like look they Full combo the first 30 seconds then proceed to die within the next 10.
by equACHOO-,sorry its equinox October 5, 2023
Get the fnf syndromemug. 
A scrunkly
by SpiderWritesInUrbanDictionary January 12, 2022
Get the Ruby from FNFmug. by Kma1423 May 6, 2022
Get the FNFmug. It's a rapping/beatboxing game of four arrows, left,down,up,right. There are 7 weeks you can play and 12 characters that want to rap battle with you. The difficulties are easy,normal,hard and there's 22 songs.
by Tomas tronico July 17, 2023
Get the Fnfmug. An abbreviation of Friday Night Funkin', basically a newgrounds.com where you "rap" against a kid with a gun, an attractive dad and milf and two spoopy kids
by no1414 March 18, 2022
Get the fnfmug.