The antonyms for the word "un-blocking" would be blocking, obstructing, impeding, hindering, or halting. These words describe the opposite meaning, suggesting the action of stopping or slowing down the flow of something. For example, if someone is blocking a road, it means that they are preventing cars or pedestrians from passing through. Similarly, a blocked pipe will prevent the water from flowing smoothly. In contrast, un-blocking would be removing the obstruction or obstacle, allowing the flow to resume. Therefore, understanding the antonyms for "un-blocking" is essential to communicate clearly and accurately in any context.