The term 'SERIES START' is composed of two crossword solutions: OPENER (6 letters) and PARTONE (7 letters). The term 'SERIES START' is used to describe the beginning of a series, such as a television show, movie, book, or other type of media. The word OPENER refers to the first episode or installment of the series, while PARTONE refers to the first part of the series. Together, these two words indicate the start of a series.