Play peacemaker is a term used to describe someone who intervenes in a dispute between two or more parties in order to bring about a peaceful resolution. It is often used to refer to someone who is able to mediate between two sides and help them reach an agreement. The term is also used to refer to someone who is able to bring about a sense of harmony and understanding between two or more people. INTERVENE, the nine letter solution to this crossword, is a verb meaning to come between two or more parties in order to settle a dispute or bring about a peaceful resolution.