English to English

verb (v)

• cause to be bitter or resentful(verb.emotion)

  Synonym:
  acerbate, embitter
  

  source: wordnet30
• add poison to(verb.change)

  Synonym:
  poison
  

  source: wordnet30
• To taint or impregnate with venom, or any substance noxious to life; to poison; to render dangerous or deadly by poison, as food, drink, a weapon; as, envenomed meat, wine, or arrow; also, to poison (a person) by impregnating with venom.(verb)

  source: webster1913