Collagenous is a term that describes something that contains or relates to collagen, a structural protein found in connective tissues. Synonyms for this word include collagenic, collagen-containing, and collagenlike. Another synonym is fibrous, as collagen makes up a significant portion of the fibers in tendons, ligaments, and skin. Other possible synonyms include cartilaginous, as collagen is also found in cartilage, and scleroprotein, which refers to any fibrous protein. Overall, there are many words that can be used to describe something that contains or is related to collagen, depending on the context and intended meaning.