antagonist

Noun

antagonist (plural antagonists)

1. An opponent or enemy.
   • our antagonists in these controversies[1594], Richard Hooker, edited by J[ohn] S[penser], Of the Lawes of Ecclesiastical Politie, […], London: […] Iohn Windet, […], →OCLC, (please specify the page)
   • Antagonist of Heav’ns Almightie King1667, John Milton, “Book IX”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC; republished...
2. One who antagonizes or stirs.
3. A chemical that binds to a receptor but does not produce a physiological response, blocking the action of other agonist chemicals, such as endogenous chemical messengers.
   • 2001: The calcium antagonists represent one of the top ten classes of prescription drugs in terms of commercial value, with worldwide sales of nearly $10 billion in 1999. — Leslie Iversen, Drugs: A Very Short Introduction (Oxford 2001, p. 41)

   Synonyms:

   blocker

4. The main character or force opposing the protagonist in a literary work or drama.
   • So God forbid I'm seen just as an average human being / I mean, imagine if antagonists lacked any evil scheme2022, Will Wood (musician), “The Main Character”, in In case I make it,, performed by Will Wood
5. A muscle that acts in opposition to another.
   • A flexor, which bends a part, is the antagonist of an extensor, which extends it.