antithesis
n.the direct opposite of something. You use this when you want to show that two things are completely different from each other.
n.the direct opposite of something; a person or thing that is the exact opposite of another. Often used in philosophical or literary contexts to highlight a sharp contrast.
“The quiet library is the antithesis of the noisy nightclub.”
“In many ways, the modern city is the antithesis of the peaceful countryside where he grew up.”
“The philosopher argued that the pursuit of wealth is the antithesis of true happiness, suggesting that material gain often leads to a loss of personal freedom.”
Borrowed from Latin antithesis, itself a borrowing from Ancient Greek ἀντίθεσις (antíthesis). By surface analysis, anti- + thesis.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.