obstructionist

n. one who intentionally and systematically interferes; hinderer of legislation, filibusterer

Obstruction is the act of blocking or impeding some passage:Obstruction theory, in mathematics, a name for any of several theoriesObstruction of justice, the crime of interfering with law enforcementObstructing government administrationPropagation path obstruction, in telecommunicationsSingle Vegetative Obstruction Model
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Noun
1. someone who systematically obstructs some action that others want to take
(synonym) obstructor, obstructer, resister, thwarter
(hypernym) disputant, controversialist, eristic
(hyponym) naysayer

n. obstructionist, one who intentionally and systematically interferes; hinderer of legislation, filibusterer

(n.)
One who hinders progress; one who obstructs business, as in a legislative body.
  

(a.)
Of or pertaining to obstructionists.