oar

Concise Oxford English Dictionary © 2008 Oxford University Press:
oar/ɔː(r)/

▶noun a pole with a flat blade, used to row or steer a boat through the water.

■ a rower.

▶verb propel with or as if with oars.

– phrases
put (or stick) one's oar in informal, chiefly Brit. give an opinion without being asked.

– derivatives
oared adjective,
oarless adjective.

– origin OE ār, of Gmc origin.