/puy'euh near"/ , 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.
7. to act as a pioneer.
v.t.
8. to be the first to open or prepare (a way, settlement, etc.).
9. to take part in the beginnings of; initiate: to pioneer an aid program.
10. to lead the way for (a group); guide.
adj.
11. being the earliest, original, first of a particular kind, etc.: a pioneer method of adult education.
12. of, pertaining to, or characteristic of pioneers: pioneer justice.
13. being a pioneer: a pioneer fur trader.
[ 1515-25; pionier, OF peonier foot soldier. See PEON, -EER ]
Syn. 2. leader, trailblazer, forerunner, pathfinder.