lumbagon.[L., fr. lumbus loin. See Lumbar.] (Med.) A rheumatic pain in the loins and the small of the back.()a.[L. lumbus loin. See Loin.] (Anat.) Of, pertaining to, or near, the loins; as, the lumbar arteries.()Lumbar region (Anat.), the region of the loin; specifically, a region between the hypochondriac and iliac regions, and outside of the umbilical region.()