[I_complete_me]

FYI

yack n 1: noisy talk [syn: {yak}, {yack}, {yakety-yak}, {chatter}, {cackle}]

      v 1: talk incessantly and tiresomely [syn: {yack}, {jaw}, {yack
           away}, {rattle on}, {yap away}]

[petepete]

Yeah I thought it was just a slang term. It's not a common word in Britain at all.