squamocolumnar junction

noun

squa·​mo·​co·​lum·​nar junction ˌskwā-mō-kə-ˌləm-nər- 

: the region in the uterine cervix in which the squamous lining of the vagina is replaced by the columnar epithelium typical of the body of the uterus and which is a common site of neoplastic change