The definition of a pioneer is the first person to do something, like to explore a new territory or to enter a military action.(noun)
An example of a pioneer is are early Americans who settled the old west.
See pioneer in Webster's New World College Dictionary
Origin: Fr pionnier < OFr peonier, foot soldier < peon: see peon
See pioneer in American Heritage Dictionary 4
Origin: French pionnier
Origin: , from Old French peonier, foot soldier
Origin: , from peon
Origin: , from Medieval Latin pedō, pedōn-
Origin: , from Late Latin, one who has broad feet
Origin: , from Latin pēs, ped-, foot; see ped- in Indo-European roots.
Learn more about pioneer