Yard

The Yard (abbreviation yd, plural sometimes yds) is a unit of length in the Imperial System and United States Customary Units.
The word "yard" comes from the Anglo-Saxon word for a straight rod.
History.
A yard has always been 3 feet, although the length of a foot has changed frequently throughout history. In 1959, the International Yard and Pound Agreement was signed between the United Kingdom, South Africa, Australia, the United States, New Zealand and Canada. It was defined as 0.9144 metres. The United States continued to use the old yard under the name 'Survey Yard'
Usage.
Roadsigns in the United Kingdom are in miles and yards, rarely in Canada and the Republic of Ireland. It can also be used as a measure of area (square yard) and as a measure of volume (cubic yard). It is also used to measure pitches and fields for a number of sports that originated from English speaking countries. It finds seldom use in other metricated Commonwealth Nations.