The word "un-barred" suggests that something has been released or opened after being previously blocked by a bar or obstacle. Antonyms for "un-barred" would be words that suggest inhibition, obstruction or prevention. For example, "barred" itself, "blocked," "closed," "constricted," "held back," "restricted, "sealed," "shut" are all words that could translate as antonyms for "un-barred". These antonyms suggest something that is held in, imprisoned, or constrained in some way, and unable to move freely. Overall, the antonyms for "un-barred" emphasize the idea of an obstruction or constraint that prevents something from being released or freed.