<p><strong>Noun</strong></p><ul><li>a person who is among those who first enter or settle a region, thus opening it for occupation and development by others.</li><li>a person, group, or thing that is first or among the earliest in any field of inquiry, enterprise, or development: a woman who was a pioneer in cancer research; vehicles that were pioneers of automotive engineering.</li><li>Synonyms: innovator, groundbreaker, trailblazer, leader</li><li>one of a group of foot soldiers detailed to make roads, dig intrenchments, etc., in advance of the main body.</li><li>Ecology. an organism that successfully establishes itself in a barren area, thus starting an ecological cycle of life.</li><li>Pioneer, Aerospace. one of a series of U.S. space probes that explored the solar system and transmitted scientific information to earth.</li><li>Pioneer, (formerly) a member of a Communist organization in the Soviet Union for children ranging in age from 10 to 16.</li></ul><p><strong>Verb (used without object)</strong></p><ul><li>to act as a pioneer.</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>to be the first to open or prepare (a way, settlement, etc.).</li><li>to take part in the beginnings of; initiate: to pioneer an aid program.</li><li>to lead the way for (a group); trailblaze.</li></ul><p><strong>Adjective</strong></p><ul><li>being the earliest, original, first of a particular kind, etc.: a pioneer method of adult education.</li><li>of, relating to, or characteristic of pioneers: pioneer justice.</li><li>being a pioneer: a pioneer fur trader.</li></ul>