One who designs or acts in a way that obstructs others, making it difficult or impossible to do what needs to be done. Frequently uses conflict of interest to obstruct others. Also known as an asshole or duh-weeb, and most likely proud of it.
When you have to drive six blocks just to go around the corner, it's a good sign that the engineer who planned the city's one-way streets was an obstructionist.
For more examples, see bureaucracy, committee mentality, legislator, attorney, and corporation.
One who systematically impedes or interrupts progress.
The person blocking the middle of the shopping isle that does not realize your presence.
someone who attempts to impede passage of legislation by the use of delaying tactics.