Vas"e*line (?), n. [Said by the manufacturer to be derived from G.
wasser water + Gr. 'e`laion olive oil.] A yellowish translucent
substance, almost odorless and tasteless, obtained as a residue in the
purification of crude petroleum, and consisting essentially of a
mixture of several of the higher members of the paraffin series. It is
used as an unguent, and for various purposes in the arts. See the Note
under Petrolatum. [Written also vaselin.]
Vase"-shaped` (?), a. Formed like a vase, or like a common flowerpot.
Vas"i*form (?), a. [L. vas a vessel + -form.] (Biol.) Having the form
of a vessel, or duct.
Vasiform tissue (Bot.), tissue containing vessels, or ducts.
Vas`o*con*strict"or (?), 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.
Vas`o*den"tine (?), n. [L. vas a vessel + E. dentine.] (Anat.) A
modified form of dentine, which is permeated by blood capillaries;
vascular dentine.
Vas`o*di*lat"or (?), 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.
Vas`o*form"a*tive (?), a. [L. vas a vessel + formative] (Physiol.)
Concerned in the development and formation of blood vessels and blood
corpuscles; as, the vasoformative cells.
Vas`o-in*hib"i*to*ry (?), a. (Physiol.) See Vasodilator.
Vas`o*mo"tor (?), 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.
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.
Vas"sal (?), n. [F., fr. LL. vassallus, vassus; of Celtic origin; cf.
W. & Corn. gwas a youth, page, servant, Arm. gwaz a man, a male. Cf.
Valet, Varlet, Vavasor.]
1. (Feud. Law) The grantee of a fief, feud, or fee; one who holds land
of superior, and who vows fidelity and homage to him; a feudatory; a
feudal tenant. Burrill.
2. A subject; a dependent; a servant; a slave. "The vassals of his
anger." Milton.
Rear vassal, the vassal of a vassal; an arriere vassal.
Vas"sal, a. Resembling a vassal; slavish; servile.
The sun and every vassal star.
Keble.
Vas"sal, v. t. To treat as a vassal; to subject to control; to enslave.
[Obs.] Beau. & Fl.