Word Origin & History
yard (2)
"measure of length," O.E. gerd (Mercian), gierd (W.Saxon) "rod, stick, measure of length," from W.Gmc. *gazdijo, from P.Gmc. *gazdaz "stick, rod" (cf. O.S. gerda, O.Fris. ierde, Du. gard "rod;" O.H.G. garta, Ger. gerte "switch, twig," O.N. gaddr "spike, sting, nail"), from PIE *gherdh- "staff, pole" (cf. L. hasta "shaft, staff"). In O.E. it was originally a land measure of roughly 5 meters (a length later called rod, pole or perch). Modern measure of "three feet" is attested from 1377 (earlier rough equivalent was the ell of 45 inches, and the verge). In M.E., the word also was a euphemism for "penis" (cf. "Love's Labour's Lost," V.ii.676). Slang meaning "one hundred dollars" first attested 1926, Amer.Eng. Yardstick is 1816. The nautical yard-arm (1553) retains the original sense of "stick." In 19c. British naval custom, it was permissible to begin drinking when the sun was over the yard-arm.
[yahrd] 
,