An opponent or enemy.
A muscle that acts in opposition to another.
A chemical that binds to a receptor but does not produce a physiological response, blocking the action of agonist chemicals.
The main character or force opposing the protagonist in a literary work or drama.
One who antagonizes or stirs.
Something beyond compare; a thing with which there is no comparison.
Not able to be compared.
So much better than another as to be beyond comparison; matchless or unsurpassed.