What does "erythematous, or, "erythma" mean?

Erythema (from the Greek erythros, meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries.[1] It occurs with any skin injury, infection, or inflammation. Examples of erythema not associated with pathology include nervous blushes. Image: classic bull's eye rash due to Lyme Disease.