bulky

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

• adjective Having considerable bulk; massive.
• adjective Of large size for its weight.
• adjective Clumsy to manage; unwieldy.

from The Century Dictionary.

• Of great bulk or size; large.
• Unwieldy; clumsy.
• Synonyms Bulky, Massive, Massy, Ponderous, Burly. Bulky refers to prominence, excess, or unwieldiness of size; it applies properly to material things; if applied to persons, it implies the development of physical size at the expense of higher qualities. Massy is, strictly, poetic for massive. The two denote weight and solidity quite as much as size, while that which is bulky may be hollow and comparatively light: as, a bulky bundle of straw; a massive jaw; “ingots of massy gold.” Ponderous primarily denotes weight and not size, but has come to have a secondary suggestion of unwieldiness. Burly is applicable only to persons, and expresses bigness, solidity, and force, with something of coarseness of manner.

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

• adjective Of great bulk or dimensions; of great size; large; thick; massive.

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

• adjective Being large in size, mass, or volume.
• adjective Unwieldy
• adjective bodybuilding Having excess body mass, especially muscle.

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

• adjective of large size for its weight