incompletion Syllabification: (in·com·ple·tion)Pronunciation: /ˌinkəmˈplēSHən, ˌiNG-/Definition of incompletion noun 1the state of lacking something or of having failed to complete something:humans with their profound sense of incompletion 2 Football a forward pass that is not completed. incompletion in other Oxford dictionaries Definition of incompletion in the British & World English dictionary