eff

verb (used with or without object), interjection

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

noun

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

Verb Phrases

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

1. efficient, efficiency.
2. effective, effectiveness.

verb

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

1943, euphemism for fuck, representing the sound of its first letter. Related: Effing.