The action or fact of cutting off access to a place, etc., with a roadblock or roadblocks; (more generally) the blocking of a road. Also figurative: obstruction, hindrance.
1920s; earliest use found in The Atlanta Constitution. From road + blocking.
That blocks a road or roads; that functions as a roadblock. Also figurative: that impedes or obstructs the progress of something.
1920s; earliest use found in The Ogden Standard-Examiner. From road + block + -ing.