Yard
Yard (abbreviation: yd) is a unit of length in several different systems including United States customary units, Imperial units and the former English units. It is equal to 3 feet or 36 inches. Under an agreement in 1959 between Australia, Canada, New Zealand, South Africa, the United Kingdom and the United States, the yard (known as the “international yard” in the United States) was legally defined to be exactly 0.9144 metres.[3] Prior to that date, the legal definition of the yard when expressed in terms of metric units varied slightly from country to country.
Yoke
Top of a double-hung window.