rudder

Rudder comes from Old English rōþor ("oar, rudder"), from Proto-West Germanic *rōþr, from Proto-Germanic *rōþrą, built from *rōaną, meaning "to row," plus an instrumental suffix *-þrą. That root traces back to Proto-Indo-European *h₁reh₁- ("to row").

The word began as a tool-name meaning simply "oar" — the thing you row with — before narrowing to mean the steering blade at a boat's stern.

Rudder is akin to Old English rōwan, the ancestor of modern "row," since both grew from the same Germanic root for the act of rowing.