WordWeb Online

1. Hinder or prevent the progress or accomplishment of
   "His brother obstructed him at every turn";
   - blockade, block, hinder, stymie, stymy [rare], embarrass
    
2. Block passage through
   "obstruct the path";
   - obturate, impede, occlude, jam, block, close up
    
3. Shut out from view or get in the way so as to hide from sight
   "The trees obstruct my view of the mountains";
   - block

Derived forms: obstructed, obstructing, obstructs

Type of: conceal, entrammel [literary], fetter [literary], forbid, foreclose, forestall, hide, hinder, impede, preclude, prevent, trammel [literary]

Encyclopedia: Obstruct