Super-Duper Tuesday n. a day that many US states hold primary elections in which political parties choose their candidates for the presidential election to be held the following November; Tsunami Tuesday. Editorial Note: “Duper” serves as an informal superlative via reduplication of “super.” Super-Duper Tuesday is so named because more primaries would be held on that day than have been held in previous years on Super Tuesday, possibly making later primaries irrelevant by establishing strong front-running candidates before the parties’ conventions later in the year. (source: Double-Tongued Dictionary)