Hast odor, also known as malodorous or foul-smelling, can be a source of embarrassment for some people. There are many synonyms for the word hast odor, including pungent, putrid, rancid, stinky, noxious, fetid, rank, acrid, foul, and nauseating. These words all describe an unpleasant and offensive smell. Different situations can give rise to hast odor, such as poor hygiene, spoiled food, or serious medical conditions. The causes of hast odor can be treated, and people can take steps to prevent it. Using deodorants, practicing good hygiene, and seeking medical attention, if necessary, can help alleviate the condition.