'chorioamnionitis' originates from Greek, specifically the words 'chorion' and 'amnion' and the suffix '-itis', where 'chorion' meant 'membrane around the embryo', 'amnion' meant 'inner fetal membrane', and '-itis' meant 'inflammation'.

'chorioamnionitis' was formed in Neo-Latin/medical usage by combining the classical elements 'chorio-' + 'amnion' + '-itis' and entered modern medical English as the term for inflammation of the fetal membranes.

Initially the components referred specifically to anatomical membranes ('chorion' and 'amnion'); over time the combined medical term came to denote the clinical condition of inflammation (usually infectious) affecting those membranes.