Stinkstone is a term used to describe a type of rock with a particularly unpleasant odor. However, there are several synonyms available for it that can be used interchangeably. Some common synonyms for stinkstone include fetid rock, malodorous rock, and smelly rock. Each of these terms communicates the same underlying concept as stinkstone without being overly specific. Other possible synonyms could include foul rock, noxious rock, or rank rock. Depending on the context in which it is being used, any of these terms can serve as an effective substitute for stinkstone when talking about rocks or minerals with an unpleasant odor.