synovia

(si-no'vi-ah) [G. syn, together, L. ovum, egg.] Joint-oil, a clear viscid fluid secreted by a synovial membrane, the function of which is to lubricate the joint or the surfaces of an enclosed tendon, or to serve as a water-pad in a bursa. It consists mainly of mucin with some albumin, fat, epithelium, and leucocytes.