rangy

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Having long slender limbs.
• adjective Inclined to rove.
• adjective Providing ample range; roomy.

from The Century Dictionary.

• Said of an animal, especially a cow, which has a long and small barrel or body and narrow hind quarters, with unusual space between the front and hind legs. A rangy cow may be good for beef, but is poor for dairy purposes.
• Mountainous.
• In stock-breeding, adapted for ranging or running about, or indicating such adaptation; quick or easy in movement; of roving character or capability: as, a rangy yoke of oxen (that is, good travelers, capable of making good speed, as in plowing); rangy steers (that is, steers disposed to wander away to a distance, as on a stock-range).
• Having or permitting range or scope; roomy: commodious.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Inclined or able to range, or rove about, for considerable distances; apt or suited for much roving, -- chiefly used of cattle.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Slender and long of limb; lanky
• adjective Prone to roaming around with animal-like movements.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective tall and thin and having long slender limbs
• adjective allowing ample room for ranging
• adjective adapted to wandering or roaming