chloramphenicolPronunciation: /ˌklɔːramˈfɛnɪkɒl/Definition of chloramphenicol noun [mass noun] Medicine an antibiotic used against serious infections such as typhoid fever. Origin: 1940s: from chloro- (representing chlorine) + am(ide) + pheno- + ni(tro-) + (gly)colchloramphenicol in other Oxford dictionaries Definition of chloramphenicol in the US English dictionary