In pathology, "lordosis" means an abnormal forward curvature of the spine in the lumbar region that results in a swaybacked posture, according to Dictionary.com. In zoology, "lordosis" can also mean a downward arching posture assumed by female mammals during mating.
The noun "lordosis" first appeared in the English language in 1704 through Modern Latin, but it originates from the Greek word "lordosis," states Online Etymology Dictionary. The Greek word "lordos" means bent backwards, and the suffix "-osis" expresses a state or condition, explains Online Etymology Dictionary. In medical terminology, "-osis" indicates a state of disease. Thus, "lordosis" is a diseased state involving a bending back.