'unblock' definitions:

Definition of 'unblock'

From: WordNet
verb
Clear or remove an obstruction from; "the procedure unblocked his arteries"
verb
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
verb
Make (assets) available; "release the holdings in the dictator's bank account" [syn: unblock, unfreeze, free, release] [ant: block, freeze, immobilise, immobilize]

Synonyms of 'unblock'

From: Moby Thesaurus