The word is a combination between the two words "fucking" and "nigger". Its origin wasn't meant offensive to anyone, only for private use. The guys who originally used it only used it for lulz. It could also be associated with expressing hate towards the negro race. This is not its favored use, though
"Fnnnnnnnnnnnnnnnnn..." (Where they don't directly saythe word "fnigger", but sort of refer to it)
(FFF-nigger) A person of First Nation descent who finds himself or herself believing they are from a US ghetto and dress, act and talk like a nigger. Very much like a wigger only red skin.
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.