O

n An implement for impelling a boat, being a slender piece of timber, usually ash or spruce, with a grip or handle at one end and a broad blade at the other. The part which rests in the rowlock is called the loom. An oar is a kind of long paddle, which swings about a kind of fulcrum, called a rowlock, fixed to the side of the boat. An oarsman; a rower; as, he is a good oar.

 - (Zool.) An oar like swimming organ of various invertebrates.

 - Oar cock (Zool), the water rail.

 - Spoon oar, ...