interstitial UK /ɪntəˈstɪʃəl/US /ɪntəɹˈstɪʃəl/noun 2adjective 1forms 1 noun2 •(Internet) A web page, usually carrying advertising, displayed when leaving one content page for another.An interstitial appeared before the download. •An interstitial discontinuity in a crystal.The second mechanism, which is the primary focus of the present paper, involves insertion of interstitials into dangling bonds at the surface. — 2008 adjective1 •Of, relating to, or situated in an interstice.The novel's interstitial chapters. formsinterstitials
