Source : WordNet®

eff
     v : have sexual intercourse with; "This student sleeps with
         everyone in her dorm"; "Adam knew Eve"; "Were you ever
         intimate with this man?" [syn: {roll in the hay}, {love},
          {make out}, {make love}, {sleep with}, {get laid}, {have
         sex}, {know}, {do it}, {be intimate}, {have intercourse},
          {have it away}, {have it off}, {screw}, {fuck}, {jazz},
         {hump}, {lie with}, {bed}, {have a go at it}, {bang}, {get
         it on}, {bonk}]

Source : Free On-Line Dictionary of Computing

EFF
     
        {Electronic Frontier Foundation}