Webster's New World Medical Dictionary

necrosis, gangrenous
Tissue death that is due
to the combined effects of blood-flow stoppage and
bacterial infection.
necrotic
Dead. For example, necrotic tissue is
dead tissue.
necrotizing fasciitis
Severe bacterial infection
of the fascia, the tissues that line and separate mus-
cles, that causes extensive tissue death. Necrotizing
fasciitis can be caused by several different types of
bacteria, particularly by virulent strains of strepto-
coccus and staphylococcus. The rapid spread and
destruction of tissue occurs because of substances
produced by the bacteria. Treatment involves the
use of high-dose antibiotics and surgical removal of
dead and infected tissue to help control the infec-
tion. Also known as flesh-eating bacteria.
needle aspiration, fine
See 
fine needle
aspiration.
needle biopsy
See 
biopsy, needle.
needle biopsy, stereotactic
See 
biopsy, stereo-
tactic needle.
negative, false
See 
false negative.
neglect, child
See 
child abuse.
Neisseria
A group of bacteria that includes the
bacterium that causes gonorrhea.
nematode
A parasitic roundworm.
neo-
Prefix meaning new, as in neonate (a new-
born baby) and neoplasm (an abnormal new
growth, a tumor).
neonatal
Pertaining to the newborn period,
specifically the first 4 weeks after birth.
neonatal jaundice
See 
jaundice, neonatal.
neonatal mortality rate
The number of chil-
dren under 28 days of age who die, divided by the
number of live births in that year. 
neonatal sepsis
A bacterial infection of the
blood in a neonate, an infant younger than 4 weeks
of age. Babies with sepsis may be listless, overly
sleepy, floppy, weak, and very pale. Neonatal sepsis
is life-threatening.