oar

noun3

1. •
   A type of lever used to propel a boat, having a flat blade at one end and a handle at the other, and pivoted in a rowlock atop the gunwale, whereby a rower seated in the boat and pulling the handle can pass the blade through the water by repeated strokes against the water's resistance, thus moving the boat.
2. •
   An oarsman; a rower.

   • He is a good oar.
3. •
   An oar-like swimming organ of various invertebrates.

verb1

1. •
   (literary) To row; to travel with, or as if with, oars.

noun1

1. •
   Initialism of original aspect ratio.