ob·struc·tion / əbˈstrəkshən; äb-/ • n. the action of obstructing or the state of being obstructed: they faced obstruction in carrying out their research walkers could proceed with the minimum of obstruction. ∎  a thing that impedes or prevents passage or progress; an obstacle or blockage: the tractor hit an obstruction. ∎  (in various sports) the action of unlawfully obstructing a player on the opposing team. ∎ Med. blockage of a bodily passageway, as the intestines. ∎  Law the action of deliberately hindering a legal process.

obstruction (ŏb-struk-shŏn) n. the condition of being blocked, which may affect any tubular organ or structure. intestinal o. blockage of the intestines, producing symptoms of vomiting, distension, and abdominal pain; failure to pass flatus or faeces (complete constipation) is usual. The causes may be acute (e.g. hernia) or chronic (e.g. tumours, Crohn's disease).
—obstructive (ŏb-struk-tiv) adj.