Antithesis means the exact opposite.
Antithesis is a noun.
Synonyms: contrast, reverse, inverse, converse.
Note: In literature, an antithesis is the opposition of one idea against another in the same sentence.
Communism is the antithesis of democracy.
We were not surprised when Sai and Durga broke off their engagement. They are the antithesis of each other.
An example of literary antithesis is "To be or not to be."