rheumatoid factor rheumatoid arthritis • rheumatoid spondylitis · · · Info · Definitions · Characters · · rheumatoid factor · · Text Common · · Latin · · Scripts 17 · · Length 6 · · Syllables Definitions · · · (noun) autoantibody that is usually present in the serum of people with rheumatoid arthritis. Synonyms: rheumatoid factor. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 f latin small letter f U+0066 h latin small letter h U+0068 i latin small letter i U+0069 m latin small letter m U+006D o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074 u latin small letter u U+0075