Webster's New World Medical Dictionary

ovary, dermoid cyst of the
See 
ovarian 
teratoma.
ovary cyst, follicular
See 
cyst of the ovary,
follicular.
overgrowth
Excessive growth. Also sometimes
called gigantism.
overgrowth syndrome
A condition with multi-
ple features, most notably excessive growth. A num-
ber of overgrowth syndromes affect children, such
as fragile X syndrome. Excessive growth of specific
body parts is also a feature of a number of disor-
ders, such as Beckwith-Wiedemann syndrome, in
which there is macroglossia (a large tongue due to
overgrowth of the tongue). Overactivity of the pitu-
itary gland with overproduction of growth hormone
causes overgrowth before adolescence and a dis-
tinctive pattern of overgrowth called acromegaly.
See also 
acromegaly; fragile X syndrome.
overload, iron
See 
excess iron.
over
-
the
-
counter drug
A drug that is available
without a prescription, in contrast to prescription
drugs that require a physician’s order. Abbreviated
OTC.
overweight
Weighing more than is healthy for a
particular body type and build. Overweight is often
defined as having a body mass index (BMI) from 25
up to 30. See also 
body mass index; obese.
ovulation
The release of the ripe egg (ovum)
from the ovary. The egg is released when the cavity
surrounding it (the follicle) breaks open in
response to a hormonal signal. Ovulation occurs
around 14 or 15 days from the first day of the
woman’s last menstrual cycle. When ovulation
occurs, the ovum moves into the Fallopian tube and
becomes available for fertilization.
ovum
An egg within the ovary of the female. An
ovum can combine with sperm to form a zygote.
oximetry
The process of determining the level of
oxygenation in arterial blood, an important meas-
ure of whether the heart and lungs are working
properly. Oximetry may be done continuously dur-
ing certain medical treatments or surgery, or it may
be done sporadically to monitor a patient’s health.