Webster's New World Medical Dictionary

vestibular system
A system that is composed 
of the vestibular apparatus, the vestibulocochlear
nerve, and the parts of the brain that interpret 
and respond to information derived from those
structures.
vestibule
In medicine and dentistry, a space or
cavity at the entrance to a canal, channel, tube, or
vessel. For instance, the front of the mouth is a
vestibule.
vestibule, vaginal
See 
vaginal opening.
vestibule of the ear
A cavity in the middle of the
bony labyrinth in the inner ear.
vestibulocochlear nerve
A nerve that is respon-
sible for the sense of hearing and that is also perti-
nent to the senses of balance and body position.
Problems with the vestibulocochlear nerve may
result in deafness, tinnitus (ringing or noise in the
ears), dizziness, vertigo, and vomiting. The vestibulo-
cochlear nerve is the eighth cranial nerve.
vestigial
Referring to a vestige (remnant) or a
primitive structure and no longer believed to be
important. For example, the appendix is considered
a vestigial organ, and some infants are born with
vestigial tails.
VHL syndrome
von Hippel-Lindau syndrome.
viable
Capable of life. For example, a viable pre-
mature baby is one who is able to survive outside
the womb.
Vibrio
A group of bacteria that includes Vibrio
cholerae, the agent that causes cholera. Other
species are common in salt and fresh water as well
as soil. Vibrio move about particularly actively.
Vibrio cholerae
One of the Vibrio bacteria, the
agent that causes cholera. See also 
cholera.
vidian neuralgia
See 
cluster headache.
Vincent gingivitis
See 
acute membranous 
gingivitis.