[ ef ]
/ ɛf /

verb (used with or without object), interjection

fuck: Stop effing around and get to work!Eff you, you lout!


the word “fuck”; the f-word: peppering his speech with superfluous and highly offensive effs.

Verb Phrases

eff off, Go away!: Eff off and die, you piece of Martian scum!

Origin of eff

1940–45; euphemism for fuck, with eff as spelled form of the name of the initial letter

Definition for eff (2 of 2)


efficient, efficiency.
effective, effectiveness.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for eff

/ (ɛf) /


euphemism for fuck taboo eff off
eff and blind slang to use obscene language

Derived forms of eff

effing, noun, adjective, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012