WordWeb Online

1. [Brit, vulgar, informal] Have sexual intercourse
   - sleep together, love, make love, sleep with, have sex, know [archaic], do it [informal], be intimate, have intercourse, lie with [archaic], bed [informal], get it on [informal]
    
2. Utter obscenities or profanities
   "The drunken men were effing loudly in the street";
   - curse, cuss [informal], blaspheme, swear, imprecate, eff and blind [Brit]

Derived forms: effs, effing, effed

Type of: copulate, couple, express, give tongue to, mate, pair, utter, verbalise [Brit], verbalize

Encyclopedia: Eff