antagonist meaning

Noun: antagonist  an'tagunist

1. Someone who offers opposition
   - adversary, opponent, opposer, resister 
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

Derived forms: antagonists

See also: antagonism, antagonistic

Type of: antagonistic muscle, drug, individual, mortal, person, somebody, someone, soul

Antonym: agonist, synergist

Encyclopedia: Antagonist

[Medicine]
n : an agent that acts in physiological opposition ‹contact between a tooth and its antagonist in the opposing jaw›: as
a : a muscle that contracts with and limits the action of an agonist with which it is paired —called also antagonistic muscle —compare AGONIST 1 SYNERGIST 2
b : a chemical that acts within the body to reduce the physiological activity of another chemical substance (as an opiate); esp : one that opposes the action on the nervous system of a drug or a substance occurring naturally in the body by combining with and blocking its nervous receptor —compare AGONIST 2

Examples

More:   Next

1. he wondered what his antagonist was doing.
2. the thing is to know the nature of your antagonist.
3. the result was the entire reconstruction of the navies of both the antagonists.
4. we both thought the best resource was flight, when pursued by so formidable an antagonist.
5. a noncompetitive antagonist prevents the agonist from producing any effect at a given receptor site.