opacify Syllabification: (o·pac·i·fy)Pronunciation: /ōˈpasəˌfī/Definition of opacify verb (opacifies, opacifying, opacified) technical make or become opaque. Derivatives opacificationPronunciation: /ōˌpasəfiˈkāSHən/ noun opacifier noun opacify in other Oxford dictionaries Definition of opacify in the British & World English dictionary