n. (Feud. Law) See Vavasor. [ 1913 Webster ]

a. (Physiol.) 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. [ 1913 Webster ]

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

n. [ L. vas a vessel + E. dentine. ] (Anat.) A modified form of dentine, which is permeated by blood capillaries; vascular dentine. [ 1913 Webster ]

a. [ L. vas a vessel + dilator. ] (Physiol.) Causing dilation or relaxation of the blood vessels; as, the vasodilator nerves, stimulation of which causes dilation of the blood vessels to which they go. These nerves are also called vaso-inhibitory, and vasohypotonic nerves, since their stimulation causes relaxation and rest. [ 1913 Webster ]

n. [ L. vas a vessel + dilator. ] (Medicine & Physiology) A substance which causes dilation of blood vessels. [ PJC ]

a. [ L. vas a vessel + formative. ] (Physiol.) Concerned in the development and formation of blood vessels and blood corpuscles; as, the vasoformative cells. [ 1913 Webster ]

a. [ See Hyper-, and Tonic. ] See Vasoconstrictor. [ 1913 Webster ]

a. [ See Hypo-, and Tonic. ] See Vasodilator. [ 1913 Webster ]

a. (Physiol.) See Vasodilator. [ 1913 Webster ]

a. [ L. vas a vessel + motor that which moves fr. movere to move. ] (Physiol.) Causing movement in the walls of vessels; as, the vasomotor mechanisms; the vasomotor nerves, a system of nerves distributed over the muscular coats of the blood vessels. [ 1913 Webster ]

Vasomotor center, the chief dominating or general center which supplies all the unstriped muscles of the arterial system with motor nerves, situated in a part of the medulla oblongata; a center of reflex action by the working of which afferent impulses are changed into efferent, -- vasomotor impulses leading either to dilation or constriction of the blood vessels. [ 1913 Webster ]

n. [ OE. vavasour, OF. vavassor, vavassour, F. vavasseur, LL. vavassor, probably contr. from vassus vassorum vassal of the vassals. See Vassal. ] (Feud. Law) The vassal or tenant of a baron; one who held under a baron, and who also had tenants under him; one in dignity next to a baron; a title of dignity next to a baron. Burrill. “A worthy vavasour.” Chaucer. [ Also written vavasour, vavassor, valvasor, etc. ] [ 1913 Webster ]

Vavasours subdivide again to vassals, exchanging land and cattle, human or otherwise, against fealty. Motley. [ 1913 Webster ]

n. [ F. vavassorie. ] (Feud. Law) The quality or tenure of the fee held by a vavasor; also, the lands held by a vavasor. [ 1913 Webster ]