The term 'Roman Septet' refers to a group of seven hills located in Rome, Italy. The five-letter solution for the crossword is 'HILLS' and the three-letter solution is 'VII'. These two solutions refer to the seven hills of Rome, which are known as the Seven Hills of Rome. The seven hills are the Palatine Hill, Aventine Hill, Capitoline Hill, Quirinal Hill, Viminal Hill, Esquiline Hill, and Caelian Hill.