A linear measure of 16.5 feet WordNet 3.0 & Open English WordNet

The rod, perch, or pole is a surveyor's tool and unit of length of various historical definitions. Wikipedia

Unit of measure for length Wikipedia Disambiguation

A unit of length equal to 51⁄2 yards, or 161⁄2 feet : also known as a rod, or a perch Wikipedia Disambiguation

An Imperial unit of length, also known as the pole or perch Wikipedia Disambiguation

Unit of length Wikidata

A cubic measure of stonework equal to 16.6 × 1.5 × 1 feet. Wiktionary

A unit of length, equal to a rod (1⁄4 chain or 5+1⁄2 yards). Wiktionary

Unit of length. Wiktionary (translation)

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. Wiktionary