This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. Introduction of evidence which conclusively establishes that a belief or hypothesis is not true or which diminishes the acceptability of a belief or hypothesis.

n. A particular fact, observation, or other item of evidence which shows or tends to show that a belief or hypothesis is not true.

"Over the years, I have tried to help people see that this contentious debate is not purely a matter of "the evidence," but instead deeply involves such things as stereotypes, confirmation bias, disconfirmation bias, and tribalism."

disconfirm