The word Rod may have one of the following meanings.
A rod is a straight and slender stick; a wand; a cylinder hence, any slender bar, as of wood or metal (applied to various purposes). (Example: Cuisenaire rods)
The rod is supposedly a species of creature that flits about in the air at such a high speed as to not be seen by the naked eye, but which can be caught on video. See: Rod (cryptozoology).
Edouard Rod was a French-Swiss novelist, 1857-1910.