Salt of sorrel is a compound with a tangy flavor derived from the plant sorrel. While there are no direct synonyms for this term, there are alternative ways to describe the essence of this unique seasoning. One could refer to it as "sorrel salt" or even "tart herb seasoning". Another option could be to highlight its citrus-like taste by calling it "zesty sorrel seasoning" or "lemony herbal salt". In essence, any phrase that emphasizes the tangy, zingy, or citrusy qualities of salt of sorrel can effectively convey its distinctive flavor profile.