The process of removing neutral cards from defenders’ hands so that they have no safe exit when they are thrown in (given the lead). You can bring about elimination by cashing winners or ruffing losers.
As South, playing in 6♦, you receive a spade lead. You win with the ace and draw trumps. You want to make the opponents lead hearts, saving you from having to guess who holds the queen.
Before giving up the lead, you must play three rounds of clubs, ruffing the third, to eliminate the suit. Then, when you concede a spade, the defenders will have no safe exit.