Pyritous is an adjective that describes something that is infused with or containing pyrite, which is a mineral that looks like gold. However, there are several synonyms for the word Pyritous, such as pyritic, auriferous, and fool's gold. Pyritic refers to something that contains pyrite, while auriferous implies something that contains gold. Fool's gold is a term that is often used to describe pyrite because of its resemblance to the precious metal. Other synonyms that can be used in place of Pyritous includes pyrite-bearing, pyrite-laden, and pyritiferous. These synonyms can be used interchangeably depending on the context of the sentence or paragraph.