"roadblock" in the noun sense
1. barrier, roadblock
any condition that makes it difficult to make progress or to achieve an objective
"intolerance is a barrier to understanding"
2. roadblock, barricade
a barrier set up by police to stop traffic on a street or road in order to catch a fugitive or inspect traffic etc.
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License