stonewall - obstruct or hinder any discussion; "Nixon stonewalled the Watergate investigation"; "When she doesn't like to face a problem, she simply stonewalls"

foreclose, forestall, preclude, prevent, forbid - keep from happening or arising; have the effect of preventing; "My sense of tact forbids an honest answer"

filibuster - obstruct deliberately by delaying; of legislation

check - block or impede (a player from the opposing team) in ice hockey

hang - prevent from reaching a verdict, of a jury

bottleneck - slow down or impede by creating an obstruction; "His laziness has bottlenecked our efforts to reform the system"

block off, blockade - obstruct access to

barricado, barricade - block off with barricades

barricade - prevent access to by barricading; "The street where the President lives is always barricaded"

asphyxiate, suffocate, stifle, choke - impair the respiration of or obstruct the air passage of; "The foul air was slowly suffocating the children"

tie up - restrain from moving or operating normally; "Traffic is tied up for miles around the bridge where the accident occurred"

dam, dam up - obstruct with, or as if with, a dam; "dam the gorges of the Yangtse River"

block out, screen - prevent from entering; "block out the strong sunlight"

earth up, land up - block with earth, as after a landslide

barricade, block, block up, blockade, block off, bar, stop - render unsuitable for passage; "block the way"; "barricade the streets"; "stop the busy road"

clog, clog up, congest, choke off, foul, back up, choke - become or cause to become obstructed; "The leaves clog our drains in the Fall"; "The water pipe is backed up"

hinder, impede - be a hindrance or obstacle to; "She is impeding the progress of our project"

barricade, block, block up, blockade, block off, bar, stop - render unsuitable for passage; "block the way"; "barricade the streets"; "stop the busy road"

conceal, hide - prevent from being seen or discovered; "Muslim women hide their faces"; "hide the money"