Antimonic is a rare adjective that refers to something related to antimony, a chemical element with the symbol Sb. There are several synonyms for this word, including antimonial, stibic, and stibious. Antimonial is perhaps the most common of these, and it is often used to describe various medicinal and industrial applications of antimony. Stibic and stibious are more technical words that are typically employed in chemistry and other scientific fields. Regardless of which term you use, they all mean essentially the same thing: related to antimony or its compounds.