A more publicly usable alternative for the word Fucking.
Generally used as an Adjective, like to emphasize something.
The word Fuck is
refferred to as the
F-Word generally,
so "Fucking" would be F-Word with an "ing",
so that would be F-ing, and this is pronounced as "Ef-ing" and this evolved into "Effing" or "
Efing" being an alternative for Fucking.
The "g" in "Effing" isn't required to get the desired pronounciation, so it is omitted, giving our result of "Effin" or "F-in"