The term 'bad-smelling' can be described by four words: FETID (5 letters), ACRID (5 letters), RANCID (6 letters), and FOUL (4 letters). FETID is an adjective meaning having an extremely unpleasant smell, often associated with decay. ACRID is an adjective meaning having a sharp, bitter, and unpleasant smell or taste. RANCID is an adjective meaning having a strong, unpleasant smell or taste caused by the process of decomposition. Finally, FOUL is an adjective meaning having an unpleasant smell. All of these words describe something that has an unpleasant odor.