Meaning

noun any painful disorder of the joints or muscles or connective tissues

noun a chronic autoimmune disease with inflammation of the joints and marked deformities; something (possibly a virus) triggers an attack on the synovium by the immune system, which releases cytokines that

originFirst attested 1601, from Latin rheumatismus (“rheum”), from Ancient Greek ῥευματισμός (rheumatismós, “humour, discharge, rheum”) from ῥευματίζομαι (rheumatízomai, “to suffer from a rheum”) from ῥεῦμα (rheûma, “stream, flow”) from ῥέω (rhéō, “to flow”)

Etymology from Wiktionary, CC BY-SA 3.0