rheumatoid adjective 2noun 1forms 3 adjective2 •Involving or pertaining to rheumatism, especially rheumatoid arthritis.Rheumatoid sufferers have such pain and discomfort every day of their lives that they live eternally in high hopes of something effective turning up. — 1976 •(old-fashioned) Presenting analogies with rheumatism. noun1 •(old-fashioned) A person with rheumatoid arthritis. formsrheumatoids · more rheumatoid · most rheumatoid