"having a long, slender form, quick or easy in movement" (as an animal suited to ranging), 1845, from range (v.) + -y (2). Also "adapted for ranging" (1868). Of landscapes, "hilly," 1862, Australian English (probably from range (n.)). Of persons of a long, slender form by 1899. Related: Ranginess.
As a rule, we hold that the Jersey should be "growthy," deep-flanked, and loose-jointed, and should have, generally, the characteristics which farmers know as "rangy." [American Agriculturalist, November 1876]