The term 'Professional Prefix' refers to a job title prefix that is used to denote a certain level of expertise or experience in a particular field. The crossword solution for this term is 'PARA', which is an abbreviation for 'Paralegal'. A Paralegal is a professional who assists lawyers in their work, such as researching legal documents and preparing cases for trial. They are not qualified to practice law, but they can provide valuable support to attorneys.