underscore Syllabification: (un·der·score)Translate underscore | into Italian Definition of underscore noun Pronunciation: /ˈəndərˌskôr/ a line drawn under a word or phrase for emphasis. (on a computer or typewriter keyboard) a short horizontal line (_) on the baseline. verb Pronunciation: /ˈəndərˌskôr, ˌəndərˈskôr/ [with object] underline (something). emphasize:the company underscored the progress made with fuel cellsunderscore in other Oxford dictionaries Definition of underscore in the British & World English dictionary