syncytial UK /sɪnˈsɪt.i.əl/US /sɪnˈsɪʃ.(i.)əl/ adjective2 •Of or pertaining to a syncytium.The epithelium, however, in many regions has a more syncytial appearance due to loss of cell boundaries. — 1906 •Characterized by interdependence and a sense of mutual identity. formsmore syncytial · most syncytial