disconfirm
Concise Oxford English Dictionary © 2008 Oxford University Press:
disconfirm/dɪskənˈfəːm/
▶verb show that (a belief or hypothesis) is not or may not be true.
– derivatives
disconfirmation /ˌdɪskɒnfəˈmeɪʃ(ə)n/ noun,
disconfirmatory adjective.
disconfirmation /ˌdɪskɒnfəˈmeɪʃ(ə)n/ noun,
disconfirmatory adjective.
'disconfirm' also found in these Oxford entries:

