Webster's New World Medical Dictionary

Nonoxynol-9
A potent spermicide (sperm-
killing agent) used as a contraceptive.
nonpathogenic
Incapable of causing disease.
For example, nonpathogenic E. coli are E. coli bac-
teria that do not cause disease, but instead live nat-
urally in the large intestine.
non-rapid eye movement sleep
See 
NREM
sleep.
nonseminoma
A type of testicular cancer that
arises in specialized sex cells called germ cells that
give rise to sperm. Nonseminomas include embry-
onal carcinoma, teratoma, choriocarcinoma, and
yolk sac tumor.
non-small-cell lung cancer
Cancer of the lung
that is not small cell carcinoma. It may be bron-
chogenic carcinoma, squamous cell carcinoma, ade-
nocarcinoma, or large cell carcinoma of the lung.
The distinction between small and non-small-cell
lung cancers is made under the microscope.
Knowing which type a patient has is important for
proper therapy. The treatment options for non-small-
cell lung cancer are generally different than those for
small cell lung cancer.
nonsteroidal anti-inflammatory drug
See
NSAID.
nonsyndromic
Not part of a syndrome. Hearing
loss, for instance, can be syndromic or nonsyn-
dromic. See also 
syndrome.
Noonan syndrome
A congenital malformation
syndrome that is characterized by mildly short
stature, a congenital heart defect, a broad or
webbed neck, an unusual chest shape (prominent
above and caved in below), low-set nipples, a char-
acteristic facial appearance, and, in boys, testes that
do not descend normally into the scrotum (cryp-
torchidism). Abbreviated NS. Although NS was once
called Turner-like syndrome, it is a distinctive entity
that affects both males and females and carries an
elevated risk of developmental and language delay,
learning disabilities, hearing loss, and mild mental
retardation. NS is inherited in an autosomal domi-
nant manner. It is relatively common, with an esti-
mated incidence of 1 in 1,000–2,500 live births.
Mutations in multiple genes, including the KRAS and
PTPN11 genes, can cause Noonan syndrome.