A stick, pole, or bundle of switches or twigs (such as a birch), used for personal defense or to administer corporal punishment by whipping.
An implement resembling and/or supplanting a rod (particularly a cane) that is used for corporal punishment, and metonymically called the rod, regardless of its actual shape and composition.
A stick used to measure distance, by using its established length or task-specific temporary marks along its length, or by dint of specific graduated marks.
An implement held vertically and viewed through an optical surveying instrument such as a transit, used to measure distance in land surveying and construction layout; an engineer's rod, surveyor's rod, surveying rod, leveling rod, ranging rod. The modern (US) engineer's or surveyor's rod commonly is eight or ten feet long and often designed to extend higher. In former times a surveyor's rod often was a single wooden pole or composed of multiple sectioned and socketed pieces, and besides serving as a sighting target was used to measure distance on the ground horizontally, hence for convenience was of one rod or pole in length, that is, 5½ yards.
(biology) Any of a number of long, slender microorganisms.
(chemistry) A stirring rod: a glass rod, typically about 6 inches to 1 foot long and 1/8 to 1/4 inch in diameter that can be used to stir liquids in flasks or beakers.
(slang) A hot rod, an automobile or other passenger motor vehicle modified to run faster and often with exterior cosmetic alterations, especially one based originally on a pre-1940s model or (currently) denoting any older vehicle thus modified.
(ufology) A rod-shaped object that appears in photographs or videos traveling at high speed, not seen by the person recording the event, often associated with extraterrestrial entities.
(mathematics) A Cuisenaire rod.
(rail transport) A coupling rod or connecting rod, which links the driving wheels of a steam locomotive.
