Obstructor Synonyms

Someone who systematically obstructs some action that others want to take
(Noun)
Synonyms:
  1. obstructionist
  2. obstructer
  3. resister
  4. thwarter
Any structure that makes progress difficult
(Noun)
Synonyms:
  1. obstruction
  2. obstructer
  3. impediment
  4. impedimenta