a protein in the blood of a normal fetus, occasionally reappearing in an adult, where its presence indicates the possibility of disease or, in a pregnant woman, of fetal malformations
See alpha-fetoprotein in American Heritage Dictionary 4
(ălˌfə-fēˌtō-prōˈtēn, -tē-ĭn)
noun Abbr. AFP
An antigen produced in the liver of a fetus that can appear in certain diseases of adults, such as liver cancer. Its level in amniotic fluid can be used in the detection of certain fetal abnormalities, including Down syndrome and spina bifida.