A person instrumental in the growth of something, especially in its early stages
Preceding all others in time
One who prepares the way
One in the vanguard of civilization
A military engineer
He was the pioneer of British canoeing.
Atlanta owes its origin to the development of pioneer railroads of Georgia.
James calls his work the "last word" of the earlier stage of psychology, but he was in reality the pioneer of the new.
For Dr. Howe is the great pioneer on whose work that of Miss Sullivan and other teachers of the deaf-blind immediately depends.
Like Lessing, whose work he immediately continued, he was a pioneer of the golden age of this literature.