Where does “eff” come from?
eff (English) comes from English ineffable, from Middle French ineffable, from Latin ineffābilis, from Latin effabilis, from Latin -bilis, from Proto-Italic -ðlis, from Proto-Indo-European -dʰlis, from Proto-Indo-European -dʰlom — Alternative form of *-trom; instrumental suffix;...
eff (English): Fuck
Ancestry of “eff”, step by step