9 Q Without U Words for Words With Friends
early 15c., "watery," later "of or pertaining to serum" (16c.), from French séreux (16c.) and directly from Latin serosus, from serum "watery fluid, whey" (see serum). Related: Serosity.
serous se·rous (sēr'əs)adj. Containing, secreting, or resembling serum.