Ferreous is a word commonly used to describe something that is made of or contains iron. However, there are a number of other words that can be used as synonyms for ferreous, such as ferric, which also refers to iron. Other words that can be used as synonyms for ferreous include metallic, steel-like and iron-rich. These words can be used to describe a variety of objects and substances that contain iron, including steel pipes, iron filings, and magnetite. By using these synonyms, you can add more variety to your writing and help your readers understand the specific qualities of the objects you are describing.