Third-person singular present of 'eff,' meaning to say or spell out the letter F, or euphemistically to express using the F-word.
A playful alteration or representation of the letter F itself; used as a euphemistic verb to avoid saying explicit words, especially common in the phrase 'eff off' (milder version of a cruder phrase).
Language has always had 'minced oaths'—polite ways to say rude things—and 'eff' is a modern version where the letter name itself becomes the euphemism, letting people express frustration while technically being more polite.
Complete word intelligence in one call. Free tier — 50 lookups/day.