English Reference

Word

eff

UK/ˌiːˌɛfˈɛf/

Definitions

01euphemism for 'fuck'

C2

v. to use a softer word instead of the 'F-word' when you are angry or want to swear politely.

v. to serve as a euphemistic substitute for the expletive 'fuck', often used to maintain a degree of decorum while expressing frustration.

“I am so tired of this job, I just want to eff off and never come back.”

“He was so frustrated with the bureaucratic delays that he told the clerk to eff off, though he immediately regretted the outburst.”

Informal · Slang · Humorous

Usage

Often used in the phrasal verbs 'eff off' or 'eff up'.

Synonyms

mess upscrew up

02the letter F

B2

n. the name of the letter 'F' when you write it out as a word.

n. the phonetic representation or name of the Latin script letter 'F'.

“The word 'fish' starts with an eff.”

“The typographer noted that the descender on the lowercase eff was slightly too long for the chosen line spacing.”

Usage

Usually spelled 'ef' or 'eff'.

03to express in words

C2

v. to put a feeling or idea into words.

v. to express or articulate something in words; the verbal counterpart to 'ineffable'.

“It is hard to eff the beauty of the mountains in a simple poem.”

“The philosopher struggled to eff the transcendental experience, eventually concluding that some truths remain beyond the reach of language.”

Literary · Formal

Usage

Rare in modern English; most commonly encountered in its negated adjective form 'ineffable'.

Real-World Examples

“Vincent has caring parents, but the film’s central message is that at some point every generation has to tell the previous one to eff off, as well-meaning as they may be.”
The Guardian · 28 Aug 2026

Etymology

A variant spelling of the letter f, the initial letter of fuck. Compare pee.

Back-formation from ineffable, ultimately from Latin effor (“utter”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domains

ElectronicsInternetPolitics

This entry

Level
C2 · Proficiency
Frequency
Frequent
Updated

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