FIHN stands for "feigned interest head nodding", basically this is something one performs while stuck in a unwanted one-way conversation with an unbearable bullshitter, more often than not they are older people.
You start doing FIHN's as your drunk Uncle Dan once again ropes you into enduring a different iteration of how he lost his hand, last time it was a great white shark, this time it was a bloody knife duel with a Gurkha in the jungles of Nepalis when in fact it was nothing more than an untreated infection.
by hadoukentotheface June 1, 2020