- orConnects at least two alternative words, phrases, clauses, sentences, etc., each of which could make a passage true.
- oarA 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.