rotten

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

• adjective Being in a state of putrefaction or decay; decomposed.
• adjective Having a foul odor resulting from or suggestive of decay; putrid.
• adjective Made weak or unsound by rot.
• adjective Morally corrupt or despicable.
• adjective Very bad; wretched.
• adverb To a very great degree.

from The Century Dictionary.

• noun A dialectal variant of ratten.
• Good for nothing; trashy; mean; detestable.
• Undergoing natural decomposition; affected by rot or organic dissolution; putrid (as animal and some vegetable matters), soft (as fruits, etc.), or weak (as vegetable fibers, fabrics, etc.) from elemental decay: as, a rotten carcass or egg; a rotten log or plank; rotten cloth.
• Putrid from organic decay, or from the presence of decomposing matter; hence, of a putrid quality; ill-smelling; fetid.
• Affected with the disease called rot, as sheep or other animals.
• Unsound as if from rotting; in a loose or disintegrated state; soft or friable; yielding: as, rotten iron or stone.
• Unsound in character or quality; in a corrupt or untrustworthy state; destitute of stability or integrity.
• In printing, said of bad prints from woodcuts, that show holes and broken lines.

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

• adjective Offensive to the smell; fetid; disgusting.
• adjective Not firm or trusty; unsound; defective; treacherous; unsafe.
• adjective See under Borough.
• adjective (Min.) a soft stone, called also Tripoli (from the country from which it was formerly brought), used in all sorts of finer grinding and polishing in the arts, and for cleaning metallic substances. The name is also given to other friable siliceous stones applied to like uses.

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

• adjective Of perishable items, overridden with bacteria and other infectious agents.
• adjective In a state of decay.
• adjective Cruel, mean or immoral.
• adjective Bad or terrible.
• adverb To an extreme degree.

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

• adjective damaged by decay; hence unsound and useless
• adjective very bad
• adjective having decayed or disintegrated; usually implies foulness