polychlorinatedbiphenols Share definition Flag PCB, a carcinogenic chemical that can cause genetic mutations. Yo, Bubba...yo mamma aroun' a buncha polychlorinatedbiphenols in her third trimester befo' you was born? polychlorinatedbiphenols by megnao flimpis July 6, 2003 Get the polychlorinatedbiphenols mug.