noun. One who opposes and contends against another; an adversary.

noun. The principal character in opposition to the protagonist or hero of a narrative or drama.

noun. A muscle that counteracts the action of another muscle, the agonist.

noun. A drug or chemical substance that interferes with the physiological action of another, especially by combining with and blocking its nerve receptor.

noun. One who contends with another in combat or in argument; an opponent; a competitor; an adversary.

noun. In anatomy, a muscle which acts in opposition to another: as, a flexor, which bends a part, is the antagonist of an extensor, which extends it.

Counteracting; opposing; combating: as, antagonist forces; an antagonist muscle.

adjective. Antagonistic; opposing; counteracting.

noun. One who contends with another, especially in combat; an adversary; an opponent.

noun. A muscle which acts in opposition to another.

noun. A medicine which opposes the action of another medicine or of a poison when absorbed into the blood or tissues.

noun. An opponent or enemy.

noun. One who antagonizes or stirs.

noun. A chemical that binds to a receptor but does not produce a physiological response, blocking the action of agonist chemicals.

noun. The main character or force opposing the protagonist in a literary work or drama.

noun. a drug that neutralizes or counteracts the effects of another drug

noun. someone who offers opposition

noun. a muscle that relaxes while another contracts