obstructiing or tending to obstruct; obstructive.

the fact of being obstructive, tending to obstructive; obstructiveness.

something that obstructs, blocks or closes up with an obstacle or obstacles; an obstacle, obstruction or hindrance.

a man who obstructs, hinders, thwarts another's or other's progresss, course of action, etc.

that which nullifies, prevents the effect of a cause.