The phrase "smelt high heaven" refers to an intensely strong and unpleasant odor. If you're looking for alternatives to this phrase, here are some synonyms that can be used to describe a foul and pungent smell: stench, reek, funk, odor, smell, aroma, fragrance. You could also use idioms such as "stank to high heaven" or "smelled like a skunk." Additionally, some adjectives that could be used to describe an overpowering smell are: nauseating, noxious, putrid, rank, rancid, foul, and fetid. Whether you're writing an essay or simply trying to describe a particularly unpleasant smell, these synonyms for "smelt high heaven" can help you effectively convey your message.