Word Origin and History for tertiary Expand. adj. 1650s, of the third order, rank, degree, etc., from Latin tertiarius of or pertaining to a third, from tertius third, a third, from root of tres three (see three).
Water and Fluid retention in legs, also known as edema, is a medical condition caused by abnormal accumulation of water or fluids in the bodyâs tissues. Though excess water can be accumulated anywhere in the body, the most common areas are the ankles and legs.
In these diseases, edema occurs primarily because of the body's retention of too much salt (sodium chloride). The excess salt causes the body to retain water, which then leaks into the interstitial tissue spaces, where it appears as edema. Medications also can cause pitting edema. The most common local conditions that cause edema are varicose veins and thrombophlebitis (inflammation of the veins) of the deep veins of the legs.