The pilot of an aircraft speeding through the air and the pilot of a watercraft plowing through the water both drag an etymological foot on the ground. Surprisingly enough, considering its modern contexts, the English word pilot can be traced back to the Indo-European root *ped-, meaning "foot." From the lengthened-grade suffixed form *pdo- came the Greek word pdon, "blade of an oar," and in the plural, "steering oar.