flabby

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

• adjective Soft and hanging loosely or in folds.
• adjective Having a body characterized by fleshiness or softness, as from being somewhat overweight.
• adjective Lacking force, control, or effectiveness.

from The Century Dictionary.

• Without firmness or elasticity; hanging loose by its own weight; lax; flaccid: said chiefly of flesh: as, flabby cheeks.
• Figuratively, nerveless; languid; feeble; lacking substance or force: as, a flabby manner; flabby logic or rhetoric.

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

• adjective Yielding to the touch, and easily moved or shaken; hanging loose by its own weight; wanting firmness; flaccid.

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

• adjective Yielding to the touch, and easily moved or shaken; hanging loose by its own weight; wanting firmness; flaccid; as, flabby flesh.
• adjective of wine Having a slight lack of acidity; having mild sweetness.
• adjective of writing, etc. Turgid or overwrought.

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

• adjective out of condition; not strong or robust; incapable of exertion or endurance