Vasoconstrictor /(?)/

Vas·o·con·strict·or

Vasoconstrictor

a.
  1. Causing constriction of the blood vessels; as, the vasoconstrictor nerves, stimulation of which causes constriction of the blood vessels to which they go. These nerves are also called vasohypertonic. (Physiol.)

Vasoconstrictor

n.
  1. A substance which causes constriction of the blood vessels. Such substances are used in medicine to raise abnormally low blood pressure. (Medicine, Physiology)