rod

A straight, round stick, shaft, bar, cane, or staff.

A longitudinal pole used for forming part of a framework such as an awning or tent.

(fishing) A long slender usually tapering pole used for angling; fishing rod.

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.

(archaic) A unit of length equal to 1 pole, a perch, ¹⁄₄ chain, 5+¹⁄₂ yards, 16+¹⁄₂ feet, or exactly 5.0292 meters (these being all equivalent).

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, 5+¹⁄₂ yards.

(archaic) A unit of area equal to a square rod, 30+¹⁄₄ square yards or ¹⁄₁₆₀ acre.

A straight bar that unites moving parts of a machine, for holding parts together as a connecting rod or for transferring power as a driveshaft.

(anatomy) A rod cell: a rod-shaped cell in the eye that is sensitive to light.

(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 pistol; a gun.

(slang, vulgar) A penis.

(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, and some diesel shunters and early electric locomotives.