Ferruginous is a word that describes something that is rusty in color or contains iron. However, there are several synonyms that may be used instead of this word. These include words such as rust-colored, iron-hued, and rust-red. Other synonyms could be reddish-brown, maroon, coppery, or brick-dyed. When referring to animals, the term chestnut-colored may be used instead of the word ferruginous. Additionally, the word can be replaced by using the phrase "iron oxide" when referring to something that contains rust. Overall, there are many different synonyms that can be used to describe something that is ferruginous, giving writers options to vary their writing while using similar descriptions.