Do you know ghouls from goblins and ghosts?
late 14c., from Latin pus "pus, matter from a sore;" figuratively "bitterness, malice" (related to puter "rotten;" cf. putrid), from PIE *pu- (2) "to rot, decay" (cf. Sanskrit puyati "rots, stinks," putih "stinking, foul;" Greek puon "discharge from a sore," pythein "to cause to rot;" Gothic fuls, Old English ful "foul"), perhaps originally echoic of a natural exclamation of disgust.
A generally viscous, yellowish-white fluid formed in infected tissue, consisting of white blood cells, cellular debris, and necrotic tissue.
thick, opaque, usually yellowish white fluid matter formed in association with inflammation caused by the invasion of the body by infective microorganisms (such as bacteria). It is composed of degenerating leukocytes (white blood cells), tissue debris, and living or dead microorganisms. See inflammation.