'roadblock' definitions:

Definition of 'roadblock'

From: WordNet
noun
Any condition that makes it difficult to make progress or to achieve an objective; "intolerance is a barrier to understanding" [syn: barrier, roadblock]
noun
A barrier set up by police to stop traffic on a street or road in order to catch a fugitive or inspect traffic etc. [syn: roadblock, barricade]

Synonyms of 'roadblock'

From: Moby Thesaurus