A person who or (occasionally) a thing which hinders or impedes; a hinderer. Cf. let, v.2

One who interrupts: see the verb.

One who causes to turn aside; a perverter; an obstructor, hinderer. Obsolete.

One who crosses, in various senses; one who makes the sign of the cross; one who thwarts, opposes, or contravenes; one who passes over, etc.

A person who selfishly prevents another from having or enjoying something, even though he or she has no personal use for it.

One who or that which obstructs the path or action of another; an opponent, adversary, obstructor, frustrater.

A person who or thing which obstructs or hinders; = obstructor, n.

A person who or thing which obstructs; a hinderer; spec. an opponent of progress.

A person who obstructs, esp. one who delays progress. Usually in plural. Now rare.

one who filibusters.