Texting your friend a sentence-sized word when you're too lazy to respond, don't know what to say, you want to avoid the subject, and/or you don't care what they're talking about. Usually includes the word "ferf" at the middle or end of the word, but can be omitted once ferfing is normal between the friends.
The girls relationship had ended badly, so her family took her out to cheer her up. I was their waiter and after work, her family took me along for some drinks, and after a long night of drinking, I ended up being her FERF.
Mother: "Jane, you've been so sad ever since you and John broke up, why don't you go out with that waiter, he seems cute"
Jane: "What is this mom, a FERF?"
Smug and whiny, complaining to an audience of people who simply don't care. Short for "ferfy nerfy ner ferny fer", which is a catch-all phrase used to imitate the whiner.
"Martin's complaining about Vincent's intentional misuse of 'your' again. The ferfy is thick today."