A play by which a declarer only partially eliminates the suits that a defender may safely lead. Whether the defender will have to lead to declarer’s advantage depends on the distribution.
Here is an example:
As South, you arrive in 6♠. West leads the ♦J, which you ruff. You want to delay playing on hearts until you have eliminated the other suits so that if a heart finesse loses to West then he can only return a heart or give a ruff and discard.
The snag is that if you draw two rounds of trumps and ruff two clubs, dummy will be out of trumps and it will be safe for West to exit in diamonds. Accordingly, you draw only one round of trumps. Then you cash the top clubs, crossruff the minors and play a heart to the nine (or cover East’s card). Since East has the outstanding trump, the partial elimination succeeds.