Black MondayBlack" Mon`day\ 1. Easter Monday, so called from the severity of that day in 1360, which was so unusual that many of Edward III.'s soldiers, then before Paris, died from the cold. --Stow. Then it was not for nothing that my nose fell a bleeding on Black Monday last. --Shak. 2. The first Monday after the holidays; -- so called by English schoolboys. --Halliwell.