underscore UK /ˈʌn.dəˌskɔː(ɹ)/US /ˈʌn.dɚˌskoɹ/noun 2verb 2forms 3 noun2 •A line drawn or printed beneath text; the character _.He walks into the house and picks up a pen. The thought he has is a brilliant idea. He must write it down. Only two words need to be written. The underscore adds importance. / BOUNTY HUNTER — 2007 •A piece of background music. verb2 •To underline; to mark a line beneath text.By convention, Rubyists usually underscore their method names. — 2011 •To emphasize or draw attention to.I wish to underscore the importance of proper formatting. formsunderscored · underscoring · underscores