v. sl. euphem. 1 tr. & intr. (often foll. by off) = FUCK (in expletive use). 2 intr. say fuck or similar coarse slang words. øeffing and blinding using coarse slang. [name of the letter F, as a euphemistic abbr.]
EFF
Meaning of EFF in English
English main colloquial, spoken dictionary. Английский основной разговорный словарь. 2012