To establish the falsity of a claim or belief; to show or to tend to show that a theory or hypothesis is not valid.(verb)
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Use "disconfirm" in a sentence
"She asked me if this sounded like the woman Susy would bring along, and I told her I was not at liberty to confirm or disconfirm this possibility."
"When this latest worry reached me at the end of the year, I resolved to see if I could confirm (or disconfirm) the veracity of the Great Tennis Ball Fuss."
"If someone comes up with a rigorous objective method built on rigorous objective definitions, I will be sure to incorporate that and use it to confirm or disconfirm the hypotheses that have been built in the meantime."