an accumulation of jobs not done or materials not processed that are yet to be dealt with (especially unfilled customer orders for products or services)
make (assets) available; "release the holdings in the dictator's bank account"
play the cards of (a suit) so that the last trick on which a hand can follow suit will be taken by a higher card in the hand of a partner who has the remaining cards of a combined holding
clear or remove an obstruction from; "the procedure unblocked his arteries"