| 1. | an obstruction placed across a road, esp. of barricades or police cars, for halting or hindering traffic, as to facilitate the capture of a pursued car or inspection for safety violations. |
| 2. | an obstruction on a road, as a fallen tree or a pile of fallen rocks. |
| 3. | a hastily built barricade, as of barbed wire, erected across a road to hold up the advance of an enemy. |
| 4. | an action, condition, etc., that obstructs progress toward an objective: Nationalism is a roadblock to European unity. |
| 5. | to halt or obstruct with or as if with a roadblock. |