The term 'FIRST LINES' can be broken down into two crossword solutions: INTRO (5 letters) and ATEAMS (6 letters). INTRO is a term used to refer to the beginning of a book, speech, or other written work. It is often used to introduce the main characters and themes of the work. ATEAMS is an acronym for 'Advanced Technology and Engineering Automation Management Systems, ' which is a type of software used to manage complex engineering projects.