antitonic
/æntɪˈtɒnɪk/Definitions
1. adjective
Having the opposite quality or effect of tonic; opposite in tone or pitch.
“The antitonic chord in the symphony created a dramatic effect on the listeners.”
2. noun
A solution that has the opposite effect of a tonic solution, especially in medicine.
“The doctor used an antitonic solution to neutralize the poison in the patient’s body.”