What does "yard" mean?

Additional senses

1. 2.A long piece of timber, as a rafter, etc. [Obs.]
2. 3.A measure of length, equaling three feet, or thirty-six inches, being the standard of English and American measure.
3. 4.The penis.
4. 5.(Naut.) A long piece of timber, nearly cylindrical, tapering toward the ends, and designed to support and extend a square sail. A yard is usually hung by the center to the mast. See Illust. of Ship. Golden Yard, or Yard and Ell (Astron.), a popular name the three stars in the belt of Orion. -- Under yard [i. e., under the rod], under contract. [Obs.] Chaucer.
5. 6.An inclosure; usually, a small inclosed place in front of, or around, a house or barn; as, a courtyard; a cowyard; a barnyard. A yard . . . inclosed all about with sticks In which she had a cock, hight chanticleer. Chaucer.
6. 7.An inclosure within which any work or business is carried on; as, a dockyard; a shipyard. Liberty of the yard, a liberty, granted to persons imprisoned for debt, of walking in the yard, or within any other limits prescribed by law, on their giving bond not to go beyond those limits. -- Prison yard, an inclosure about a prison, or attached to it. -- Yard grass (Bot.), a low-growing grass (Eleusine Indica) having digitate spikes. It is common in dooryards, and like places, especially in the Southern United States. Called also crab grass. -- Yard of land. See Yardland.
7. 8.To confine (cattle) to the yard; to shut up, or keep, in a yard; as, to yard cows.