Definitions for "Unblock"
Keywords:  suit, trick, discard, play, card
play or discard a high card that is preventing the run of a suit.
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
make (assets) available; "release the holdings in the dictator's bank account"