Webster's New World Medical Dictionary

monostotic fibrous dysplasia
Excessive
growth in a single bone of hard-fibrous tissue that
replaces the normal bone tissue. Symptoms of
monostotic fibrous dysplasia may include pain and
fracture of the bone. Most cases are diagnosed in
adolescence or young adulthood and remain
unchanged throughout life. The outlook is usually
very good. Monostotic fibrous dysplasia appears to
be a different disorder from polyostotic fibrous dys-
plasia.
monozygous twins
Identical twins. They are
called monozygous because they originate from a
single fertilized egg (zygote).
morbidity
Illness, disease.
morbilli
See 
measles.
morgue
A place where dead bodies are kept
before autopsy, funeral, or burial.
morning sickness
The common phenomenon
of nausea between the 6th and 12th weeks of preg-
nancy. Symptoms include nausea and vomiting.
Morning sickness is believed to be caused by hor-
monal changes and metabolic changes that involve
carbohydrate digestion. Suggested treatment
includes eating crackers or other high-carbohy-
drate foods first thing in the morning (even before
getting out of bed); eating small, frequent meals;
drinking extra fluids between meals; and avoiding
fatty foods. If morning sickness is extreme enough
to lead to weight loss during pregnancy, the condi-
tion is termed hyperemesis gravidarum, and it
requires immediate medical treatment. See also
hyperemesis gravidarum.
morning-after pill
See 
contraceptive,
emergency.
morphea
Skin changes that are localized to one
or more patchy areas of skin that become hardened,
dry, smooth, and slightly pigmented. Morphea is
called “localized scleroderma” but it rarely, if ever,
evolves into full-fledged scleroderma, an autoim-
mune disease of the connective tissue.
morphine
A powerful narcotic agent that has
strong analgesic (pain relief) action and other sig-
nificant effects on the central nervous system. It is
dangerously addicting. Morphine is a naturally
occurring member of a large chemical class of com-
pounds called alkaloids. The name, which derives
from Morpheus (the mythologic god of dreams)
was coined in 1805 by German apothecary Adolf
Serturner to designate the main alkaloid in opium.
Opium comes from the poppy plant.