composed primarily of bodily fluid material pus material ENVO bodily fluid classes differ from UBERON's treatment of bodily fluids. UBERON refers to the substance itself ("S"). We assert that UBERON's classes are the primary compositional component of the terms in ENVO ("S material"). Use of the ENVO terms is typically recommended when you wish to indicate that there may be other materials intermixed with S. A bodily fluid material which is composed primarily of pus, a bodily fluid consisting of a whitish-yellow or yellow substance produced during inflammatory responses of the body that can be found in regions of pyogenic bacterial infections. Pus is produced from the dead and living cells which travel into the intercellular spaces around the affected cells. pus