When one says that something is "smelling to high heaven," it means that there is a strong, unpleasant odor emanating from it. There are several synonyms that can be used to express this idea. The most similar phrase is "stinking to high heaven." Other options include "reeking," "pungent," "foul-smelling," "odorous," "rank," "malodorous," "stinky," "putrid," and "noxious." These words can be used in a variety of contexts, from describing a pile of garbage to commenting on a person's body odor. No matter the situation, there is always a word to express the intensity of an unpleasant smell.