Webster's New World Medical Dictionary

nasal septum, deviated
Failure of the nasal
septum to be in the center of the nose and divide the
nasal passages evenly. Deviation of the nasal septum
may be congenital (present at birth) or acquired
(occur later). The major problem it causes is air-
way obstruction. A deviated septum can be cor-
rected with surgery.
nasal septum, perforated
A condition in which
the dividing wall between the two main nasal pas-
sages has been eroded away, resulting in a commu-
nication between the passages. Perforated nasal
septum can be caused by a number of conditions,
including repeated inhalation of cocaine and other
harmful drugs. It can usually be repaired with
surgery.
naso-
Prefix referring to the nose, as in nasogas-
tric tube (a tube that is passed through the nose and
to the stomach).
nasogastric
Referring to the passage from the
nose to the stomach. Abbreviated NG.
nasogastric tube
A tube that is passed through
the nose and down through the nasopharynx and
esophagus into the stomach. Abbreviated NG tube. It
is a flexible tube made of rubber or plastic, and it
has bidirectional potential. It can be used to remove
the contents of the stomach, including air, to
decompress the stomach, or to remove small solid
objects and fluid, such as poison, from the stomach.
An NG tube can also be used to put substances into
the stomach, and so it may be used to place nutri-
ents directly into the stomach when a patient cannot
take food or drink by mouth.
nasopharynx
The area of the upper throat that
lies behind the nose. See also 
oropharynx.
National Academy of Sciences
A nonprofit,
self-perpetuating society of distinguished scholars
engaged in scientific and engineering research,
dedicated to the furtherance of science and tech-
nology, and to their use for the general welfare.
Abbreviated NAS. The US Congress granted the NAS
a charter in 1863 with the authority that requires it
to advise the federal government on scientific and
technical matters.