One that opens, especially a device used to cut open cans or pry up bottle caps. Games The player who starts the betting in cards. Games Cards of sufficient value to enable the holder to open the betting. The first act in a theatrical variety show. Sports The first game in a series. for openers Informal To begin with: "Out of 54 potential jurors, they knocked 20 off . . . just for openers\u201d ( Joseph DiMona).