Pronunciation: (pī"u-nēr'),[key] —n. 1. a person who is among those who first enter or settle a region, thus opening it for occupation and development by others.
2. one who is first or among the earliest in any field of inquiry, enterprise, or progress: pioneers in cancer research. 3. one of a group of foot soldiers detailed to make roads, dig intrenchments, etc., in advance of the main body.
4. Ecol.an organism that successfully establishes itself in a barren area, thus starting an ecological cycle of life.
5. (cap.) Aerospace.one of a series of U.S. space probes that explored the solar system and transmitted scientific information to earth.
6. (cap.) (formerly) a member of a Communist organization in the Soviet Union for children ranging in age from 10 to 16. Cf. Komsomol, Octobrist.
—v.i. to act as a pioneer.
—v.t. 1. to be the first to open or prepare (a way, settlement, etc.).
2. to take part in the beginnings of; initiate: to pioneer an aid program. 3. to lead the way for (a group); guide.
—adj. 1. being the earliest, original, first of a particular kind, etc.: a pioneer method of adult education. 2. of, pertaining to, or characteristic of pioneers: pioneer justice. 3. being a pioneer: a pioneer fur trader.