yard (n.1) Look up yard at Dictionary.com
"patch of ground around a house," Old English geard "fenced enclosure, garden, court; residence, house," from Proto-Germanic *gardaz (cognates: Old Norse garðr "enclosure, garden, yard;" Old Frisian garda, Dutch gaard, Old High German garto, German Garten "garden;" Gothic gards "house," garda "stall"), from PIE *ghor-to-, suffixed form of root *gher- (1) "to grasp, enclose," with derivatives meaning "enclosure" (cognates: Old English gyrdan "to gird," Sanskrit ghra- "house," Albanian garth "hedge," Latin hortus "garden," Phrygian -gordum "town," Greek khortos "pasture," Old Irish gort "field," Breton garz "enclosure, garden," and second element in Latin cohors "enclosure, yard, company of soldiers, multitude").

Lithuanian gardas "pen, enclosure," Old Church Slavonic gradu "town, city," and Russian gorod, -grad "town, city" belong to this group, but linguists dispute whether they are independent developments or borrowings from Germanic. As "college campus enclosed by the main buildings," 1630s. In railway usage, "ground adjacent to a train station or terminus, used for switching or coupling trains," 1827. Yard sale is attested by 1976.
yard (n.2) Look up yard at Dictionary.com
measure of length, Old English gerd (Mercian), gierd (West Saxon) "rod, staff, stick; measure of length," from West Germanic *gazdijo, from Proto-Germanic *gazdjo- "stick, rod" (cognates: Old Saxon gerda, Old Frisian ierde, Dutch gard "rod;" Old High German garta, German gerte "switch, twig," Old Norse gaddr "spike, sting, nail"), from PIE root *ghazdh-o- "rod, staff, pole" (cognates: Latin hasta "shaft, staff"). The nautical yard-arm retains the original sense of "stick."

Originally in Anglo-Saxon times a land measure of roughly 5 meters (a length later called rod, pole, or perch). Modern measure of "three feet" is attested from late 14c. (earlier rough equivalent was the ell of 45 inches, and the verge). In Middle English and after, the word also was a euphemism for "penis" (as in "Love's Labour's Lost," V.ii.676). Slang meaning "one hundred dollars" first attested 1926, American English. Middle English yerd (Old English gierd) also was "yard-land, yard of land," a varying measure but often about 30 acres or a quarter of a hide.