Synonyms for Impediment (same or very similar meaning)
WordNet sense 1 (something immaterial that interferes with or delays action or progress):
balk, check, deterrent, handicap, hindrance, baulk, hinderanceWordNet sense 2 (any structure that makes progress difficult):
impedimenta, obstruction, obstructer, obstructorFrom the ODE community, based on WordNetadd/edit