/am'nee oh sen tee"sis/ , n. , pl. amniocenteses /-seez/ .
a surgical procedure for obtaining a sample of amniotic fluid from the amniotic sac in the uterus of a pregnant woman by inserting a hollow needle through the abdominal wall, used in diagnosing certain genetic defects or possible obstetric complications.
[ 1955-60; amnio- (as comb. form of AMNION) + CENTESIS ]