disconfirm

dis- +‎ confirm

disconfirm (third-person singular simple present disconfirms, present participle disconfirming, simple past and past participle disconfirmed)

1. (transitive) To establish the falsity of a claim or belief; to show or to tend to show that a theory or hypothesis is not valid.
   • 1943, Carl G. Hempel, “A Purely Syntactical Definition of Confirmation”, in The Journal of Symbolic Logic, volume 8, number 4, page 122:

     The empirical data obtained in a test—or, as we shall prefer to say, the observation sentences describing those data—may then either confirm or disconfirm the given hypothesis, or they may be neutral with respect to it.

• infirm

• confirm

• disconfirmable
• disconfirmation
• disconfirmatory

• “disconfirm”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present.
• Oxford English Dictionary, second edition (1989)