To obstruct means to block something so it cannot move or continue - like blocking a road, blocking someone's view, or blocking a plan. You can obstruct traffic (block the road), obstruct someone's view (stand in front of them), or "obstruct justice" - a serious crime where someone stops the police or a court from doing their job properly, for example by hiding facts or lying.

阻礙、妨礙;法律上常說「妨礙司法」(obstruct justice)。