antagonist meaning and definition

ANTAGONIST noun

Definition of antagonist (noun)

1. someone who offers opposition
   • synonyms: adversary, opponent, opposer, resister
   • antonym: agonist
2. a muscle that relaxes while another contracts
   • "when bending the elbow the triceps are the antagonist"
3. a drug that neutralizes or counteracts the effects of another drug
   • antonym: synergist